Development of the humeral head offset index for control of humeral torsion.

BACKGROUND: Control of humeral torsion can present a challenge, especially intraoperatively during closed reduction and fixation of humeral shaft fractures or 2-part surgical neck fractures of the proximal humerus. The objective of this study is to develop and validate an indirect method for the assessment of humeral torsion using an index that is linearly correlated with rotational arm position and can be derived from only a single plain radiographic image of the proximal humerus. METHODS: The Humeral Head Offset Index (HHOI) is calculated as the ratio of the medial and lateral offset of the humeral head measured from the outer cortices of the shaft on a plain radiographic or fluoroscopic image. The relationship of HHOI with humeral torsion was first verified on a sawbone model with radiopaque characteristics under fluoroscopic control. Different degrees of retroversion were simulated through manual rotation of the humerus with a digital protractor in 5° increments until 40° internally rotated and then in 5° increments until 40° externally rotated from the neutral position. The same procedure was subsequently performed digitally on Digitally Reconstructed Radiographs (DRRs) from computed tomography (CT) dataset of the sawbone. Next, the HHOI index was applied to eight randomly selected patients with total humerus CT using the same method. Spearman's rho was calculated for the bivariate analysis of correlation between the simulated degree of retroversion and the HHOI. Strength of correlation was classified according to Koo and Li. Interrater and intrarater reliability of three blinded observers with repetition of measurement after three months were analyzed by assessing the intraclass correlation coefficient (ICC). RESULTS: Both in the sawbone model and in DRRs, we demonstrated a high to very high significant linear correlation between simulated retroversion and the HHOI. ICC values demonstrated excellent interrater reliability and excellent intrarater reliability for measurement of the HHOI. CONCLUSIONS: The HHOI is a new, simple, reliable index that has a linear relationship to the rotation of the humerus and can therefore allow an indirect control of humeral torsion in comparison to the contralateral side.

A Posterior Acromial Bone Block Augmentation Is Biomechanically Effective at Restoring the Force Required To Translate the Humeral Head Posteriorly in a Cadaveric, Posterior Glenohumeral Instability Model.

PURPOSE: To assess the biomechanical utility of a posterior acromial bone block (PABB) for the treatment of posterior glenohumeral instability. METHODS: Ten fresh-frozen cadaveric specimens were obtained based upon an a priori power analysis. A 2.5-cm scapular spine autograft was harvested from all shoulders. A custom robot device was used to apply a 50-N compressive force to the glenohumeral joint. The humeral head was translated 10 mm posteroinferiorly at 30 degrees from the center of the glenoid at a rate of 1.0 mm/s in 6 consecutive conditions: (1) intact specimen, (2) intact with PABB, (3) posterior capsulolabral tear, (4) addition of the PABB, (5) removal of the PABB and repair of the capsulolabral tear (LR), and (6) addition of the PABB with LR. The maximum force required to obtain this translation was recorded. Paired t tests were performed to compare relevant testing conditions. RESULTS: Ten cadavers with a mean ± SD age of 54.4 ± 13.1 years and mean ± SD glenoid retroversion of 6.5 ± 1.0 degrees were studied. The PABB provided greater resistance force to humeral head translation compared to the instability state (instability, 29.3 ± 15.3 N vs PABB, 47.6 ± 21.0 N; P = .001; 95% confidence interval [CI], -27.6 to -10.0). When comparing PABB to LR, the PABB produced higher resistance force than LR alone (PABB, 47.6 ± 21.0 N; LR, 34.2 ± 20.5 N; P = .012; 95% CI, -23.4 to -4.1). An instability lesion treated with the PABB, with LR (P = .056; 95% CI, -0.30 to 20.4) or without LR (P = .351; 95% CI, -6.8 to 15.7), produced resistance forces similar to the intact specimen. CONCLUSIONS: A PABB is biomechanically effective at restoring the force required to translate the humeral head posteriorly in a cadaveric, posterior glenohumeral instability model. A posterior acromial bone block is a biomechanically feasible option to consider in patients with recurrent posterior instability. CLINICAL RELEVANCE: Augmentation of the posterior acromion may be a biomechanically feasible option to treat posterior shoulder instability.

The Long Head of the Biceps Has a Stabilizing Effect on the Glenohumeral Joint in Simulated Infraspinatus or Subscapularis but Not Supraspinatus Rotator Cuff Deficiency: A Biomechanical Study.

PURPOSE: To investigate the stabilizing role of the long head of the biceps (LHB) for different simulated rotator cuff (RC) tears. METHODS: Human cadaveric specimens (n = 8) were fixed in a robotic-based experimental setup with a static loading of the RC, deltoid, and the LHB. RC tears were simulated by unloading of the corresponding muscles. A throwing motion and an anterior load-and-shift test were simulated under different RC conditions by unloading the supraspinatus (SS), subscapularis (SSc), infraspinatus (IS), and combinations (SS + SSc, SS + IS, SS + SSc + IS). The LHB was tested in 3 conditions: unloaded, loaded, and tenotomy. Translation of the humeral head and anterior forces depending on loading of the RC and the LHB was captured. RESULTS: Loading of LHB produced no significant changes in anterior force or glenohumeral translation for the intact RC or a simulated SS tear. However, if SSc or IS were unloaded, LHB loading resulted in a significant increase of anterior force ranging from 3.9 N (P = .013, SSc unloaded) to 5.2 N (P = .001, simulated massive tear) and glenohumeral translation ranging from 2.4 mm (P = .0078, SSc unloaded) to 7.4 mm (P = .0078, simulated massive tear) compared to the unloaded LHB. Tenotomy of the LHB led to a significant increase in glenohumeral translation compared to the unloaded LHB in case of combined SS + SSc (2.6 mm, P = .0391) and simulated massive tears of all SS + SSc + IS (4.6 mm, P = .0078). Highest translation was observed in simulated massive tears between loaded LHB and tenotomy (8.1 mm, P = .0078). CONCLUSIONS: Once SSc or IS is simulated to be torn, the LHB has a stabilizing effect for the glenohumeral joint and counteracts humeral translation. With a fully loaded RC, LHB loading has no influence. CLINICAL RELEVANCE: With an intact RC, the condition of the LHB showed no biomechanical effect on the joint stability. Therefore, from a biomechanical point of view, the LHB could be removed from the joint when the RC is intact or reconstructable. However, since there was a positive effect even of the unloaded LHB in this study when SSc or IS is deficient, techniques with preservation of the supraglenoid LHB origin may be of benefit in such cases.

Humeral Head Reconstruction of Reverse Hill-Sachs Lesions.

Compared with anterior instability, posterior shoulder dislocations are a rare entity and are often missed at presentation. A concomitant anteromedial impression fracture of the humeral head, or a reverse Hill-Sachs lesion, is commonly present with these dislocations and is more pronounced with a longer timeline to reduction. Treatment of these defects ranges from nonsurgical treatment to soft-tissue procedures, bony reconstruction, and arthroplasty. Management may be dictated by various factors, such as patient demands, defect size and location, concomitant injuries, and underlying etiology. Small reverse Hill-Sachs defects without engagement can generally be treated nonsurgically or with benign neglect, whereas larger defects (>20%) often require surgery. The most reported surgical techniques are the (arthroscopic) McLaughlin and modified McLaughlin procedure, disimpaction and bone grafting, or reconstruction of the defect with autograft or with fresh (or fresh-frozen) osteochondral allograft. Finally, arthroplasty is generally required for large defects, where more than 45% to 50% of the articular cartilage is involved. Overall, reported outcomes generally reflect patient satisfaction for most patients, with a low incidence of secondary instability or posttraumatic arthritis, although better results are achieved when recognizing and treating these injuries in the more acute setting.

How anatomic should anatomic total shoulder arthroplasty be? Evaluation of humeral head reconstruction with the best-fit circle.

BACKGROUND: Humeral implant designs for anatomic total shoulder arthroplasty (aTSA) focus on anatomic reconstruction of the articular segment. Likewise, the pathoanatomy of advanced glenohumeral osteoarthritis often results in humeral head deformity. We hypothesized the anatomic reconstruction of the humeral head in aTSA risks overstuffing the glenohumeral joint. METHODS: Ninety-seven cases (52 females) of primary glenohumeral osteoarthritis in patients treated with aTSA were evaluated. Preoperative computed tomography scans were used to classify glenoid morphology according to the Walch classification. Coronal plane images in the plane of the humerus were used to determine the anatomic best-fit circle as described by Youderian et al. Humeral head thinning was determined as the distance from the center of rotation of the best-fit circle to the nearest point along the humeral articular surface. aTSA was modeled with a predicted anatomic humeral head and a simulated 4-mm polyethylene glenoid component. The change in the position of the native humerus was determined. Wilcoxon Rank Sum tests were used to evaluate differences in humeral head thinning and humeral lateralization between monoconcave and biconcave glenoid morphologies. Spearman's rank correlation coefficients were used to assess the relationship between humeral head thinning with preoperative active forward elevation and external rotation. RESULTS: The mean radius of the best-fit circle was 25.0 ± 2.1 mm. There was a mean thinning of 2.4 ± 2.0 mm (range -1.7 to 8.3). The mean percent thinning of the humeral head was 9.4% ± 7.7%. The mean humeral lateralization was 6.4 ± 2.0 mm. Humeral head thinning was not significantly associated with active forward elevation (r = -0.15, P = .14) or active external rotation (r = -0.12, P = .25). There were no significant differences in the percentage of humeral head thinning (P = .324) or humeral lateralization (P = .350) between concentric and eccentric glenoid wear patterns. CONCLUSIONS: Utilization of the best-fit circle as a guide in aTSA may risk excessive lateralization of the humerus and overstuffing the glenohumeral joint. This may have implications for subscapularis repair and healing, as well as glenoid implant and rotator cuff longevity. These findings call into question whether recreation of normal glenohumeral anatomy in aTSA is appropriate for all patients. Humeral head reconstruction in aTSA should account for glenohumeral joint volume and soft tissue contracture.

Radiographic comparison of eccentric stemmed vs. concentric stemless prosthetic humeral head positioning after anatomic total shoulder arthroplasty.

INTRODUCTION: Maintaining premorbid proximal humeral positioning is an essential consideration of anatomic total shoulder arthroplasty (aTSA), as malposition of the prosthetic humeral head can result in poor clinical outcomes. Stemless aTSA prosthetic heads are usually concentric, while stemmed aTSA prosthetic heads are typically eccentric in nature. Therefore, the purpose of this study was to compare the ability to restore native humeral head position between stemmed (eccentric) vs. stemless (concentric) aTSA. MATERIALS AND METHODS: Postoperative anteroposterior radiographs of 52 stemmed and 46 stemless aTSAs were analyzed. A best-fit circle was created using previously published and validated techniques to represent the premorbid humeral head position and axis of rotation. This circle was juxtaposed with another circle following the arc of the implant head. Next, the offset in center of rotation (COR), radius of curvature (RoC), and humeral head height above the greater tuberosity (HHH) were measured. Additionally, based on prior studies, an offset of >3 mm at any point between the implant head surface and premorbid best-fit circle was considered significant and further classified as overstuffed or understuffed. RESULTS: RoC deviation was significantly greater in the stemmed cohort than the stemless cohort (1.19 ± 1.37 mm vs. 0.65 ± 1.17 mm, P = .025). There was no statistically significant difference in deviation from premorbid humeral head between the stemmed and stemless cohorts for COR (3.20 ± 2.28 mm vs. 3.23 ± 2.09 mm, P = .800) or HHH (1.12 ± 3.27 mm vs. 0.92 ± 2.70 mm, P = .677). When comparing overstuffed implants to appropriately placed implants, there was a significant difference in overall COR deviation in stemmed implants (3.93 ± 2.51 mm vs. 1.92 ± 1.05 mm, P < .001). Superoinferior COR deviation (stemmed: 2.38 ± 3.01 mm vs. -0.61 ± 1.59 mm, P < .001; stemless: 2.70 ± 1.75 mm vs. -0.16 ± 1.87 mm, P < .001), mediolateral COR deviation (stemmed: 0.79 ± 2.65 mm vs. -0.62 ± 1.27 mm, P = .020; stemless: 0.40 ± 1.41 mm vs. -1.13 ± 1.96 mm, P = .020), and HHH (stemmed: 3.61 ± 2.73 mm vs. 0.50 ± 1.31 mm, P < .001; stemless: 3.98 ± 1.18 mm vs. 0.53 ± 1.41 mm, P < .001) were significantly different between overstuffed implants and appropriate implants in both the stemmed and stemless cohorts. DISCUSSION: Stemless and stemmed aTSA implants have similar rates of reproducing satisfactory postoperative humeral head COR with both producing COR deviation most commonly in the superomedial direction. Deviation in HHH contributes to overstuffing in both stemmed and stemless implants, COR deviation contributes to overstuffing in stemmed implants, while RoC (humeral head size) is not associated with overstuffing. Based on this study, it appears that neither eccentric nor concentric prosthetic heads are superior in recreating premorbid humeral head position.

Unexpected positive cultures of humeral head detected with dithiothreitol in primary shoulder arthroplasty.

BACKGROUND: Unexpected positive cultures (UPCs) are frequently observed in primary shoulder arthroplasty, and its clinical significance has not yet been well defined. This study aimed to evaluate the UPCs in humeral head in primary shoulder replacement and to understand if UPCs increase in patients with risk factors for contamination (previous surgery or infiltrations). METHODS: Patients undergoing total shoulder replacement were enrolled in this prospective observational study. To reduce the risk of humeral head contamination, all known procedures to reduce Cutibacterium acnes burden of the skin were implemented. Patients were divided into 2 groups, namely, patients who had undergone previous rotator cuff repair or infiltration and patients with no risk factors for contamination. All the humeral heads harvested were treated with dl-dithiothreitol, in a specific device (MicroDTTect), to increase the sensitivity of the cultures for bacterial identification. The cultures were analyzed for aerobic and anaerobic bacteria for up to 14 days. RESULTS: The UPCs' positivity rate of the 80 patients in the study was 19% (15 patients). The positivity rates for UPCs in the group with and without risk factors were 30% (12 patients) and 7.5% (3 patients), respectively. The rate of positive culture was higher in men (87%) than in women (13%). The observed positivity was due to C acnes and Peptoniphilus asaccharolyticus, both slow-growing anaerobes. CONCLUSIONS: Patients with previous surgery or infiltrations had a 4-fold higher rate of positivity for UPCs compared with patients without previous risk factors. The higher percentage of positivity in patients with risk factors could be related to changes in the joint microenvironment after shoulder procedures. We do not know whether the presence of UPCs could be associated with the development of periprosthetic infections at longer follow-up.

Biomechanics of subscapularis V-shaped tenotomy compared to standard tenotomy.

BACKGROUND: Subscapularis function is critical after anatomic total shoulder arthroplasty (aTSA). Recently, however, a technique has been described that features a chevron or V-shaped subscapularis tendon cut (VT). This biomechanical study compared repair of the standard tenotomy (ST), made perpendicular to the subscapularis fibers, to repair of the novel VT using cyclic displacement, creep, construct stiffness, and load to failure. METHODS: This biomechanical study used 6 pairs of fresh frozen paired cadaveric shoulder specimens. One specimen per each pair underwent VT, the other ST. Subscapularis tenotomy was performed 1 cm from the insertion onto the lesser tuberosity. For VT, the apex of the V was 3 cm from the lesser tuberosity. After tenotomy, each humerus underwent humeral head arthroplasty. Eight figure-of-8 sutures were used to repair the tenotomy (Ethibond Excel; Ethicon, US LLC). Specimens were cyclically loaded from 2 to 100 N at 45 degrees abduction at a rate of 1 Hz for 3000 cycles. Cyclic displacement, creep, and stiffness and load to failure were measured. RESULTS: Cyclic displacement did not differ significantly between the ST and VT from 1 to 3000 cycles. The difference in displacement between the V-shaped and standard tenotomy at 3000 cycles was 1.57 mm (3.66 ± 1.55 mm vs. 5.1 ± 2.8 mm, P = .31, respectively). At no point was the V-shape tenotomy (VT) >3 mm of average displacement, whereas the standard tenotomy (ST) averaged 3 mm of displacement after 3 cycles. Creep was significantly lower for VT in cycles 1 through 3. For all cycles, stiffness was not significantly different in the VT group compared with the ST group. Load to failure was not statistically significant in the VT compared to the standard tenotomy throughout all cycles (253.2 ± 27.7 N vs. 213.3 ± 76.04 N; P = .25, respectively). The range of load to failure varied from 100 to 301 N for standard tenotomy compared with 216 to 308 N for VT. CONCLUSION: This study showed that VT and ST demonstrated equivalent stiffness, displacement, and load to failure. VT had the benefit of less creep throughout the first 3 cycles, although there was no difference from cycle 4 to 3000. The VT had equivalent biomechanical properties to the ST at time zero, an important first step in our understanding of the technique. The VT technique warrants further clinical study to determine if the technique has clinical benefits over ST following aTSA.

Stemless reverse humeral component neck-shaft angle has an influence on initial fixation.

BACKGROUND: Stemless anatomic humeral components are commonly used and are an accepted alternative to traditional stemmed implants in patients with good bone quality. Presently, little literature exists on the design and implantation parameters that influence primary time-zero fixation of stemless reverse humeral implants. Accordingly, this finite element analysis study assessed the surgical implantation variable of neck-shaft angle, and its effect on the primary time-zero fixation of reversed stemless humeral implants. METHODS: Eight computed tomography-derived humeral finite element models were used to examine a generic stemless humeral implant at varying neck-shaft angles of 130°, 135°, 140°, 145°, and 150°. Four loading scenarios (30° shoulder abduction with neutral forearm rotation, 30° shoulder abduction with forearm supination, a head-height lifting motion, and a single-handed steering motion) were employed. Implantation inclinations were compared based on the maximum bone-implant interface distraction detected after loading. RESULTS: The implant-bone distraction was greatest in the 130° neck-shaft angle implantation cases. All implant loading scenarios elicited significantly lower micromotion magnitudes when neck-shaft angle was increased (P = .0001). With every 5° increase in neck-shaft angle, there was an average 17% reduction in bone-implant distraction. CONCLUSIONS: The neck-shaft angle of implantation for a stemless reverse humeral component is a modifiable parameter that appears to influence time-zero implant stability. Lower, more varus, neck-shaft angles increase bone-implant distractions with simulated activities of daily living. It is therefore suggested that humeral head osteotomies at a higher neck-shaft angle may be beneficial to maximize stemless humeral component stability.

Mid-term outcomes of microfracture for the treatment of focal, full-thickness cartilage defects isolated to the humeral head.

BACKGROUND: While microfracture has been shown to be an effective treatment for chondral lesions in the knee, evidence to support its use for chondral defects in the shoulder is limited to short-term outcomes studies. The purpose of this study is to determine if microfracture provides pain relief and improved shoulder function in patients with isolated focal chondral defects of the humeral head at a minimum 5-year follow-up. METHODS: Patients who underwent microfracture procedure for isolated focal chondral defects of the humeral head with a minimum follow-up of 5 years between 02/2006 and 08/2016 were included. At minimum 5-year follow-up, pre- and postoperative patient-reported outcome (PRO) measures were collected, including the American Shoulder and Elbow Surgeons (ASES), Single Assessment Numeric Evaluation (SANE), Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH), Short Form-12 (SF-12) Physical Component Summary (PCS), Visual Analog Scale (VAS) for pain, and patient satisfaction level (1 = unsatisfied, 10 = very satisfied). Demographic, injury, and surgical data were retrospectively reviewed. Surgical failure was defined as revision surgery for humeral chondral defects or conversion to arthroplasty. Kaplan-Meier analysis was performed to determine survivorship at 5 years. RESULTS: A total of 17 patients met inclusion/exclusion criteria. There were 15 men and 2 women with an average age of 51 years (range 36-69) and an average follow-up of 9.4 years (range 5.0-15.8). The median ASES score improved from 62 (range: 22-88) preoperatively to 90 (range: 50-100) postoperatively (P = .011). Median satisfaction was 8 out of 10 (range: 2-10). There was no correlation between patient age or defect size and PROs. Postoperatively, patients reported significant improvements in recreational and sporting activity as well as the ability to sleep on the affected shoulder (P ≤ .05). Three patients failed and required revision surgery. The Kaplan-Meier analysis determined an overall survivorship rate of 80% at 5 years. CONCLUSION: The presented study illustrates significant improvements for PROs, improved ability to perform recreational and sporting activities, and a survival rate of 80% at a mean of 9.4 years after microfracture for focal chondral humeral head defects.

Middle trapezius tendon transfer using Achilles allograft for irreparable isolated supraspinatus tendon tears effectively restores the superior stability of the humeral head without restricting range of motion: a biomechanical study.

BACKGROUND: Middle trapezius tendon (MTT) transfer has been suggested for promising treatment of irreparable isolated supraspinatus tendon tears (IISTTs). However, there have been no attempts to assess the biomechanical efficacy of MTT transfer. This study aims to evaluate the biomechanical efficacy of MTT transfer in the setting of IISTTs. METHODS: Eight fresh frozen cadaveric shoulders were tested in 3 conditions: (1) intact rotator cuff, (2) IISTT, and (3) MTT transfer using Achilles allograft for IISTTs. Total humeral rotational range of motion (ROM), superior translation of the humeral head, and subacromial contact characteristics were measured at 0°, 20°, and 40° glenohumeral abduction (representing 0°, 30°, and 60° shoulder abduction). Superior translation and subacromial contact pressures were measured at 0°, 30°, 60°, and 90° external rotation (ER). Two different MTT muscle loading conditions were investigated. A linear mixed effects model and Tukey post hoc test were used for statistical analysis. RESULTS: Total ROM was significantly increased after IISTT at 20° abduction (P = .037). There were no changes in total ROM following MTT transfer compared to the IISTT condition (P > .625 for all comparisons). The IISTT condition significantly increased superior translation compared to the intact rotator cuff condition in 0° and 20° abduction with all ER angles (P < .001), 40° abduction-30° ER (P = .016), and 40° abduction-60° ER (P = .002). MTT transfer significantly decreased superior translation of the humeral head at all abduction angles compared to the IISTT condition (P < .026). MTT transfer significantly decreased peak contact pressure by 638.7 kPa (normal loading) and 726.8 kPa (double loading) at 0° abduction-30° ER compared to the IISTT condition (P < .001). Mean contact pressure was decreased by 102.8 kPa (normal loading) and 118.0 kPa (double loading) at 0° abduction-30° ER (P < .001) and 101.0 kPa (normal loading) and 99.2 kPa (double loading) at 0° abduction-60° ER (P < .001). MTT transfer at 20° abduction-30° ER with 24 N loading significantly decreased contact pressure by 91.2 kPa (P = .035). CONCLUSIONS: The MTT transfer biomechanically restored the superior humeral head translation and reduced the subacromial contact pressure in a cadaveric model of IISTT, while not restricting total ROM. These findings suggest that MTT transfer may have potential as a surgical treatment for IISTTs.

Pyrocarbon humeral heads for hemishoulder arthroplasty grant satisfactory clinical scores with minimal glenoid erosion at 5-9 years of follow-up.

BACKGROUND: Hemishoulder arthroplasty (HSA) is a more conservative alternative to total shoulder arthroplasty for young and active patients with minimal glenoid erosion or deformity. Pyrocarbon humeral heads were introduced as an alternative to metallic humeral heads, which were associated with glenoid erosion in 28%-43%. The purpose of this study was to evaluate the progression of glenoid erosion and clinical scores of HSA using pyrocarbon humeral heads from short- (2-4 years) to midterm (5-9 years). METHODS: We retrieved the records of 45 consecutive patients who underwent HSA with pyrocarbon humeral heads from 2013 to 2017. Patients were evaluated radiographically and clinically at a first follow-up (2-4 years) and a second follow-up (5-9 years). Preoperative glenoid morphology was assessed using computed tomography scans, and glenoid erosion was assessed using plain radiographs according to Sperling et al. The Constant score (CS), American Shoulder and Elbow Surgeons (ASES) score, and Subjective Shoulder Value (SSV) score were assessed by an independent observer. RESULTS: From the initial cohort of 45 patients, 2 underwent revision surgery (4.4%) due to persistent pain (without signs of rotator cuff pathology or glenoid erosion) and 6 were lost to follow-up (13%), leaving 37 for outcome assessment (82%). At the first follow-up of 2.2 ± 0.4 years, all clinical scores improved substantially (CS from 29.3 ± 13.5 to 76.7 ± 14.4, ASES from 23.7 ± 15.6 to 87.0 ± 16.0, and SSV from 25.3 ± 12.2 to 84.1 ± 15.2), and at the second follow-up of 6.2 ± 1.2 years, good clinical scores were maintained (CS from 76.7 ± 14.4 to 80.8 ± 16.0, ASES from 87.0 ± 16.0 to 92.3 ± 15.0, and SSV from 84.1 ± 15.2 to 82.8 ± 18.3). At the second follow-up, glenoid erosion was moderate in 9 (24%) and severe in 3 (8.1%). When comparing with immediate postoperative radiographs, 10 shoulders exhibited progression of glenoid erosion by 1 grade (n = 9) or 2 grades (n = 1). CONCLUSION: Pyrocarbon humeral heads for HSA grant satisfactory clinical scores with minimal glenoid erosion.

Effects of humeral head stabilization intervention during aggressive manual passive stretching exercises in patients with painful stiff shoulder: a prospective, comparative study.

BACKGROUND: No reports have been published verifying the effects of manual interventions such as humeral head stabilization on improving function and reducing pain when applying aggressive manual passive stretching in patients with painful stiff shoulders. The purpose of this study was to compare clinical outcomes, such as range of motion, pain, and disability scores, in patients with painful stiff shoulders with and without humeral head stabilization intervention while applying aggressive manual passive stretching. METHODS: Fifty-six patients with painful stiff shoulders were recruited (31 with humeral head stabilization intervention and 25 without such intervention). Clinical outcomes such as active range of motion (A-ROM), pain, and disability scores were evaluated using a goniometer; measurement of activity visual analog scale (A-VAS); and Disabilities of the Arm, Shoulder and Hand (DASH) and Shoulder Pain and Disability Index (SPADI), respectively. RESULTS: All the parameters, A-ROM, A-VAS, and disability scores (DASH and SPADI) were not significantly different between the 2 groups (P > .05) before the intervention. However, after the intervention, the mean difference in A-ROM for flexion, abduction, and external and internal rotation was 18 (95% confidence interval [CI], 14.1-21.7), 31 (95% CI, 24.9-37.4), 17 (95% CI, 13.4-21.4), and 16 (95% CI, 11.6-20.9), respectively. The mean difference in A-VAS and disability scores for DASH and SPADI was -1 (95% CI, -1.5 to -0.8), -27 (95% CI, 32.3 to -22.6), and -23 (95% CI, -27.8 to -18.3), respectively. All of these measurements favored humeral head stabilization. CONCLUSION: During aggressive manual passive stretching in patients with painful stiff shoulders, humeral head stabilization intervention may be more beneficial in improving clinical outcomes such as A-ROM, A-VAS pain levels, and disability scores.

Does age affect patient outcomes after humeral head replacement in the treatment of acute proximal humeral fractures? A comparative cohort study with a minimum 10 years long-term follow-up.

BACKGROUND: Humeral head replacement (HHR) is now rarely recommended for complex proximal humeral fractures (PHFs) in older patients. However, in relatively young and active patients with unreconstructable complex PHFs, controversy still exists regarding the treatment options of reverse shoulder arthroplasty and HHR. The goal of this study was to compare the survival, functional, and radiographic outcomes of HHR in patients aged <70 years and those aged ≥70 years after a minimum 10 years follow-up. METHODS: Eighty-seven out of 135 patients undergoing primary HHR were enrolled and then divided into 2 groups based on age: <70 years and ≥70 years. Clinical and radiographic evaluations were performed with a minimum follow-up of 10 years. RESULTS: There were 64 patients (mean, 54.9 years) in the younger group and 23 patients (mean, 73.5 years) in the older group. The younger and older groups had comparable 10-year implant survivorship (98.4% vs. 91.3%). Patients aged ≥70 years had worse American Shoulder and Elbow Surgeons scores (74.2 vs. 81.0, P = .042) and lower satisfaction rates (12% vs. 64%, P < .001) than younger patients. At the final follow-up, older patients had worse forward flexion (117° vs. 129°, P = .047) and internal rotation (17 vs. 15, P = .036). More greater tuberosity complications (39% vs. 16%, P = .019), glenoid erosion (100% vs. 59%, P = .077), and humeral head superior migration (80% vs. 31%, P = .037) were also identified in patients aged ≥70 years. CONCLUSIONS: Unlike the increased risk for revision and functional deterioration over time after reverse shoulder arthroplasty for PHFs in younger patients, a high implant survival rate with lasting pain relief and stable functional outcomes could be observed in younger patients after HHR during long-term follow-up. Patients aged ≥70 years had worse clinical outcomes, lower patient satisfaction, more greater tuberosity complications, and more glenoid erosion and humeral head superior migration than those aged <70 years. HHR should not be recommended for the treatment of unreconstructable complex acute PHFs in older patient populations.

Pectoralis major pedicle bone grafting vs. tricortical iliac grafting for Neer 4-part proximal humerus fractures: a randomized controlled trial.

BACKGROUND: The risk of avascular necrosis, nonunion, or malunion is high in osteoporosis-related 4-part fractures. We evaluated the results of patients who underwent plate osteosynthesis with a vascularized pectoralis major graft compared with tricortical iliac grafting to treat 4-part proximal humerus fractures. MATERIAL AND METHODS: Thirty-four patients aged 50-75 years with Neer 4-part proximal humerus fractures were studied. Group A (n = 17) underwent osteotomy of a 2.5 ± 1 cm pectoralis major pedicle bone graft and plate application, whereas group B (n = 17) underwent plate osteosynthesis using iliac autogenous grafts. Final follow-up assessments included evaluation using Constant and American Shoulder and Elbow Surgeons scoring systems, humeral neck-shaft angle (HNSA), humeral head height, and humeral head avascular necrosis. RESULTS: Reduction loss was observed in 3 patients (17.6%) in group A, whereas it was observed in 10 patients (58.8%) in group B (P = .013). Humeral head avascular necrosis was found in 1 patient (5.8%) in group A, whereas it was found in 5 patients (29.4%) in the other group (P = .071). The HNSA was normal in 12 (70.5%) of group A patients, whereas it was normal in 6 (35.2%) of group B patients. The HNSA was weak or bad (<1200) in 29.4% of group A patients, whereas this rate was 64.7% in group B patients. Humeral head height was 2.64 ± 1.45 mm in group A and 3.66 ± 1.65 mm in group B. There were no statistically significant differences between the 2 groups in terms of Constant and American Shoulder and Elbow Surgeons scoring systems. CONCLUSION: Pectoralis major bone pedicle graft in Neer 4-part proximal humerus fractures reduces the risk of avascular necrosis and nonunion rates. Our technique yielded excellent clinical and radiological results. We achieved recovery without creating additional donor site morbidity.

Risk factors for osteonecrosis of the humeral head after internal fixation of proximal humeral fractures: a systematic review and meta-analysis.

BACKGROUND: Osteonecrosis of the humeral head (ONHH) is a severe complication after the internal fixation of proximal humeral fractures (IFPHF). The risk factors remain controversial though many studies have reported. In this research, meta-analysis was used to evaluate which surgeon-level factors can be modified to lower the risk and we hope to provide evidence-based support for preventing ONHH. METHODS: Literature was retrieved from PubMed, Cochrane Library, Embase, Web of Science, and Scopus for eligible studies published up to January 2023. The pooled odds ratios (ORs) were calculated with their corresponding 95% confidence intervals (CIs) to evaluate. STATA 15.1 software was applied for data synthesis, sensitivity synthesis, and publication bias. RESULTS: 45 articles were published between 2000 and 2022, and 2482 patients were finally included. All articles were observational research, with 7 case-control studies and 38 cohort studies, and the Newcastle Ottawa Scale (NOS) score ranged from 7 to 9. The pooled results suggested that age (OR 0.32, 95% CI 0.14-0.74, P = 0.01), reduction quality (OR 0.08, 95% CI 0.01-0.44, P = 0.00), fracture type (OR 0.44, 95% CI 0.25-0.78, P = 0.01), surgical approach (OR: 4.06, 95% CI 1.21-13.61, P = 0.02) and fixation implant (OR = 0.68, 95% CI = 0.34-1.33, P = 0.02) were risk factors for ONHH after IFPHF. According to sensitivity analysis, Begg (P = 0.42) and Egger (P = 0.68) tests, the results were stable and exhibited no publication bias. CONCLUSIONS: The study showed that age, reduction quality, fracture type, surgical approach and fixation implant were risk factors for ONHH after IFPHF, while gender, varus or valgus, timely operation, injured side, and the existence of medial support have little influence on ONHH, as they could not be considered risk factors and still need further investigations.

The morphometric parameters of the biceps brachii: cadaveric study.

BACKGROUND: The biceps brachii (BB) is a fusiform muscle comprising of two muscular bellies located in the anterior compartment of the arm. Its primary function includes elbow flexion and forearm supination. PURPOSE: The study aimed to examine the morphometric parameters of the BB in adult cadaveric specimens. METHODS: This dissection-based study examined the anatomy of the BB in 40 arms taken from 20 Thiel embalmed European cadavers, including 13 males with an average age of 81 years and seven females with an average age of 84 years. The investigation included an observational inspection of the BB morphology and collected 19 parameters, comprising the lengths and widths of the short and long head tendons and muscle bellies. RESULTS: The observation analysis showed that the anatomy of the BB consisted mainly of two muscle bellies: a short head and a long head. An additional third humeral head, originating from the anteromedial aspect of the mid of the humerus and inserted into the common biceps tendon, was observed in four (10%) specimens. The average lengths of the short head and long head were 35.98 ± 3.44 cm and 38.90 ± 3.40 cm, respectively. There was no difference in the BB parameters according to the arm sides. However, the male specimens showed greater BB parameters than the female specimens. CONCLUSION: The short head had a greater muscle belly, while the long head had a longer origin and insertion tendons. The BB parameters were correlated positively with the humerus length.

A prognostic classification of proximal humerus fractures: the cephalic extension staging.

PURPOSE: Recent publications emphasized the role of dorsomedial metaphyseal extension of humeral head as predictor of ischemia after complex proximal humerus fractures (PHFs). We evaluated on preoperative 3D CT scan of PHFs the surface of this metaphyseal extension and its prognostic value on the occurrence of avascular necrosis (AVN). METHODS: We followed a series of 25 fixations of complex PHF which had a preoperative 3D CT scan and measured the surface area of the posterior metaphyseal extension (PME) of the head. Using approximations, we calculated the ratio between the PME surface area (PMS) and the articular surface area of the head (HS). The PMS/HS ratio was analyzed against the risk of AVN. RESULTS: The measurement of the PMS/HS ratio emphasizes the significance of PME. The incidence of AVN is correlated with the magnitude of PME. Therefore, we include the PME as a fifth element in the characterization of complex PHFs and we propose a 4-stage prognostic classification based on the number of extensions of the humeral head. The head may have 3 extensions: posteromedial (PME), lesser tuberosity (LTE) and greater tuberosity (GTE). The risk of AVN decreases with the number of extensions of the head. CONCLUSION: Our study demonstrates a correlation between the occurrence of AVN and the size of PME in complex PHF cases. We propose a four-stage classification system to facilitate treatment decision-making between fixation and prosthesis.

Endosteal strut using a hydroxyapatite/poly-L-lactide mesh tube with a proximal humeral locking plate for the treatment of proximal humeral fractures.

PURPOSE: Proximal humeral fractures cause large intramedullary bone defects after humeral-head reduction. Hydroxyapatite/poly-L-lactide (HA/PLLA) materials are widely used for various fractures. However, the efficacy of endosteal strut using a HA/PLLA mesh tube (ES-HA/PLLA) with a locking plate for treating proximal humeral fractures was not reported. The purpose of this study is to examine the efficacy of ES-HA/PLLA with a proximal humeral locking plate in proximal humeral fractures. METHODS: Seventeen patients with proximal humeral fractures treated using ES-HA/PLLA with a locking plate from November 2017 to November 2021 were evaluated. The range of motion of the shoulder and postoperative complications were assessed at the final follow-up. Radiographs were evaluated to assess bone union and loss of reduction by measuring humeral-head height (HHH) and humeral neck-shaft angle (NSA). RESULTS: The average flexion and external rotation of the shoulder at the final follow-up were 137° (range, 90-180°) and 39° (range, - 10 to 60°), respectively. All fractures were united. The average HHH and NSA just after the surgery and final follow-up were 12.5 mm and 11.6 mm and 129.9° and 127.4°, respectively. Two patients presented screw perforation of the humeral head. One patient underwent implant removal due to infection. Avascular necrosis of the humeral head was observed in one patient with arthritis mutilans. CONCLUSIONS: The use of ES-HA/PLLA with a proximal humeral locking plate resulted in bone union in all patients and prevented postoperative loss of reduction. ES-HA/PLLA is one of the treatment options for proximal humeral fractures.

Assessing complications and functional outcomes in proximal humerus fracture management: a retrospective comparison between conservative and intramedullary nailing treatments.

INTRODUCTION: Fractures of the proximal end of the humerus (FPH) are the second most common fractures in the upper limb after fractures of the distal radius and are two to three times as common in women than in men. Therefore, the main objective of the present study was to compare and analyze the complications and the functional outcomes in patients with displaced FPH receiving conservative and surgical treatments with intramedullary nailing. METHODS: A retrospective cross-sectional study was conducted to establish the differences in complications risks between surgical and non-surgical treatment of the FPH. For this purpose, the clinical and radiological results of 67 consecutive patients were analyzed. RESULTS: A total of 25 patients were included in the non-surgically treated group. A total of 42 patients were included in the surgically treated group. Complications occurred in a total of 4 (16.0%) patients after the non-surgical treatment. Those included frozen shoulder (n = 2), nonunion (n = 1), and avascular necrosis of the humeral head (n = 1). Complications occurred in a total of 18 (42.6%) patients after the surgical treatment. Non-surgically treated patients had statistically significantly (p < 0.05) lower scores in the Constant-Murley scale in all of the categories. CONCLUSION: The present study demonstrates an overall prevalence of complications to be 16% in patients treated conservatively and 42.6% in patients treated surgically. In the non-surgical cohort, the frozen shoulder was the most frequently observed complication (8%). Interestingly, non-anatomical repositioning was the most prevalent complication in surgically treated patients. Due to the complexity of the FPH, we believe that the surgeon needs to have comprehensive knowledge regarding the characteristics of this fracture, the available treatment options, and the possible complications that may occur. This can enhance patient safety and provide satisfactory clinical outcomes.