Difficulty in performing activities of daily living associated with internal rotation after reverse total shoulder arthroplasty

The effect of humeral tray thickness on glenohumeral loads in a reverse shoulder 'smart' implant

PURPOSE

The aim of this study was to observe the effects of changing humeral tray thickness on the resultant of intraoperative glenohumeral joint loads using a load-sensing system (LSS).

METHODS

An rTSA was performed on fresh frozen full-body cadaver shoulders by using an internal proprietary LSS on the humeral side. The glenohumeral loads (Newtons) and the direction of the resultant force applied on the implant were recorded during four standard positions (External rotation, Extension, Abduction, Flexion) and three "complex" positions of Activity Daily Life ("behind back", "overhead reach" and "across chest"). For each position, the thickness was increased from 0 to 6 mm in a continuous fashion using the adjustment feature of the humeral system. Each manoeuvre was repeated three times.

RESULTS

All shoulder positions showed a high repeatability of the glenohumeral load magnitude measured with an intra-class correlation coefficient of over 0.9. For each position, we observed a strong but no linear correlation between humeral tray thickness and joint loads. It was a cubical correlation (rs = 0,91) with a short ascending phase, then a plateau phase, and finally a phase with an exponential growth of the loads on the humeral implant. In addition, an increase in trail-poly thickness led to a recentering of force application at the interface of the two glenohumeral implants.

CONCLUSION

This study provides further insight into the effects of humeral implant thickness on rTSA glenohumeral joint loads during different positions of the arm. Data obtained using this type of device could guide surgeons in finding the proper implant balance during rTSA.

Conjoint tendon lengthening improves internal rotation following reverse total shoulder arthroplasty: a cadaveric study

BACKGROUND

Reverse shoulder arthroplasty (RSA) is a common procedure for treating a variety of shoulder pathologies. However, many patients struggle with postoperative internal rotation (IR) deficits, which often hinder their activities of daily living. The conjoint tendon provides an anatomic barrier that can impede the postoperative IR of the shoulder, and this study aims to evaluate the effect of a conjoint tendon lengthening on the glenohumeral range of motion (ROM) following RSA.

METHODS

This study used ten fresh-frozen cadaver specimens of the upper extremity. An RSA was implanted using a standard deltopectoral approach, and the ROM was assessed postimplantation. Following this, the conjoint tendon was identified and lengthened using a tendon sheath z-plasty, and the ROM was rerecorded. Statistical significance for the ROM gains after conjoint tendon lengthening was determined with a significance level of P < .05.

RESULTS

Following the lengthening of the conjoint tendon, there were statistically significant improvements in all ROMs (P < .05). Subjects demonstrated a notable gain in IR to the back by 10.3 cm (P < .01), and all ROMs increased by at least 10°, except for forward flexion, which increased by 6° (P < .001).

CONCLUSIONS

This study suggests that lengthening the conjoint tendon improves postoperative ROM of the glenohumeral joint after RSA, offering a potential solution to considerable IR deficits that are commonly encountered post-RSA. Subsequent clinical and biomechanical studies should assess the stability of the shoulder joint following conjoint tendon lengthening.

Insertion sites of latissimus dorsi tendon transfer performed during reverse shoulder arthroplasty: A systematic review and meta-analysis

BACKGROUND

Reverse shoulder arthroplasty (RSA) with concurrent latissimus dorsi transfer (LDT) is a potential treatment option for restoration of external rotation (ER). Biomechanical studies have emphasized the importance of the insertion site location for achieving optimal outcomes. In this systematic review and meta-analysis, we aimed to describe what insertion sites for LDT are utilized during concomitant RSA and their associated clinical outcomes.

METHODS

A systematic review and meta-analysis were performed per PRISMA guidelines. We queried PubMed/MEDLINE, Embase, Web of Science, and Cochrane databases to identify articles reporting on patients who received RSA with LDT to restore ER and specified the site of tendon transfer insertion on the humerus. We first describe reported insertion sites in the literature. Secondarily, we present preoperative and postoperative range of motion and Constant score for different insertion sites as well as reported complications.

RESULTS

Sixteen studies, analyzed as 19 separate cohorts (by insertion site and tendon-transfer), reporting on 264 RSAs with LDT (weighted mean age 66 years, follow-up 39 months, 61% female) were evaluated. Of these, 143 (54%) included a concomitant teres major transfer (LDT/TMT) and 121 (46%) were LDT-only. Fourteen cohorts (14/19, 74%) reported insertion at the posterolateral aspect of the greater tuberosity, four cohorts (4/19, 21%) reported insertion site at the lateral bicipital groove, and one cohort (1/19, 5%) reported separate LDT and TMT with insertion of the TMT to the posterolateral aspect of the greater tuberosity and LDT to the lateral bicipital groove. Meta-analysis revealed no differences in range of motion or Constant score based on humeral insertion site or whether the LDT was transferred alone or with TMT. Leading complications included dislocation, followed by infection and neuropraxia. No discernible correlation was observed between postoperative outcomes and the strategies employed for tendon transfer, prosthesis design, or subscapularis management.

CONCLUSION

The posterolateral aspect of the greater tuberosity was the most-utilized insertion site for LDT performed with RSA. However, in the current clinical literature, LDT with or without concomitant TMT result in similar postoperative ROM and Constant score regardless of insertion site. Analysis of various proposed transfer sites reinforce the ability of LDT with RSA to restore both FE and ER in patients with preoperative active elevation and external rotation loss. Meta-analysis revealed significant improvements in range of motion and Constant score regardless of humeral insertion site or whether the LDT was transferred alone or with TMT, although future studies are needed to determine whether an ideal tendon transfer technique exists.

LEVEL OF EVIDENCE

IV.

Demographic-, Radiographic-, and Surgery-Related Factors Do Not Affect Functional Internal Rotation Following Reverse Total Shoulder Arthroplasty: A Retrospective Comparative Study

PURPOSE

This study aimed to identify the demographic-, radiographic-, and surgery-related factors influencing postoperative functional internal rotation (fIR) following reverse total shoulder arthroplasty (RTSA).

METHODS

In this retrospective cohort study, patients who underwent RTSA between June 2013 and April 2018 at a single institution were assigned to two groups ("IROgood" or "IRObad"). Patients were classified as having good fIR (≥8 points in the Constant-Murley score (CS) and fIR to the twelfth thoracic vertebra or higher) or poor fIR (≤2 points in the CS and fIR to the twelfth thoracic vertebra or lower) after RTSA with a single implant model. The minimum follow-up period was two years. Standardized shoulder-specific scores (Visual Analogue Scale (VAS), Simple Shoulder Test (SST), American Shoulder and Elbow Surgeons Score (ASES), Constant-Murley score (CS)) were used to assess the pre- and postoperative functional status of patients. Postoperative radiographic evaluation included the distalization shoulder angle (DSA), lateralization shoulder angle (LSA), critical shoulder angle (CSA), acromiohumeral distance (AHD), glenoid inclination (GI), medialization of the center of rotation (COR), lateralization of the humerus, and distalization of the greater tuberosity. Additionally, preoperative evaluation included rotator cuff arthropathy according to Hamada, glenoid version, anterior or posterior humeral head subluxation, and fatty infiltration of the rotator cuff according to Goutallier. Univariate analysis of demographic, surgical, radiographic, and implant-associated parameters was performed to identify factors associated with postoperative fIR. The Shapiro-Wilk test assessed the normal distribution of the data. Intergroup comparisons regarding demographic and surgery-related factors were conducted using the Mann-Whitney-U Test. Radiographic changes were compared using chi-square or Fisher's exact tests. The significance level was set at p < 0.05.

RESULTS

Of a total of 42 patients, 17 (age: 73.7 ± 5.0 years, follow-up (FU) 38 months [IQR 29.5-57.5]) were included in the "IRObad" group, and 25 (age: 72 ± 6.1 years, FU 47 months [IQR 30.5-65.5]) were included in the "IROgood" group. All patients were treated with the same type of implant (glenosphere size: 36 mm, 14.3%; 39 mm, 38.1%; 42 mm, 47.6%; neck-shaft angle: 135° in 68.0%; 155° in 32.0%) and had comparable indications. Univariate analysis did not reveal any of the investigated demographic, radiographic, or surgery-related parameters as risk factors for poor postoperative fIR (p > 0.05).

CONCLUSION

None of the investigated factors, including implant-associated parameters, influenced postoperative fIR after RTSA in this cohort.

Comparison of the clinical outcomes and temporal changes between superior capsular reconstruction and reverse total shoulder arthroplasty in patients with irreparable rotator cuff tear without osteoarthritic change

BACKGROUND

Superior capsular reconstruction (SCR) and reverse total shoulder arthroplasty (rTSA) are widely performed in patients with irreparable rotator cuff tears, including pseudoparalytic shoulder (PPS), and have shown positive clinical outcomes. However, limited studies have compared these 2 in terms of functional recovery in patients with PPS without osteoarthritic change. Thus, this study aimed to compare the clinical outcomes and to clarify the characteristics and differences in temporal changes among patients who underwent either rTSA or SCR using tensor fascia lata for PPS due to irreparable rotator cuff tear without osteoarthritic change (Hamada grade ≤3).

METHODS

We enrolled a total of 39 patients who underwent SCR (n = 20) or rTSA (n = 19 cases) with a follow-up period of 2 years. All patients were followed up at 2, 3, 4, 5, 6, 8, 10, 12, and 24 months postoperatively. Preoperative and postoperative range of motion (ROM), American Shoulder and Elbow Surgeons scores, and temporal changes in ROMs were compared between the 2 groups.

RESULTS

The SCR group had significantly better ROM than the rTSA group in flexion (146° ± 34° vs. 132° ± 23°, P = .022), abduction (147° ± 36° vs. 130° ± 23°, P = .0092), internal rotation (11 ± 3 Th10 vs. 6 ± 3 L3, P < .001), and American Shoulder and Elbow Surgeons score (84.1 ± 13.8 vs. 80.1 ± 6.1, P = .0096). While the rTSA group achieved 100° in flexion and abduction after 3 months postoperatively, the SCR group took approximately 5 months. However, the SCR group exceeded the rTSA group in flexion and abduction at six months postoperatively. In the SCR group, some patients with irreparable subscapularis tendon tears could not achieve 90° shoulder elevation. Both groups showed significant improvements in shoulder flexion and abduction compared to the preoperative state (P < .001).

CONCLUSION

Although SCR requires a longer rehabilitation period, it provides similar outcomes to rTSA after two years for nonosteoarthritic, irreparable cuff tears with pseudoparalysis.

Physiotherapy treatment for reverse total shoulder arthroplasty: Results of a patient-centred rehabilitation guideline using functional and patient-reported outcome measures

Rehabilitation after primary reverse total shoulder arthroplasty (RTSA) is accepted to be an essential component to successful outcome achievement, but successful rehabilitation approaches have yet to be well described in the literature. This retrospective review documents the outcomes of a cohort of 29 patients undergoing RTSA surgery with rehabilitation following the Upper Limb Treatment and Rehabilitation Advice (ULTRA) guideline (Appendix 1). The Oxford Shoulder Score, Quick Disabilities of the Arm, Shoulder and Hand score, range of movement (degrees of flexion, abduction and external rotation) and numerical rating score for pain were prospectively collected pre-operatively and at one- and two-years post-operatively. Scores were then evaluated to establish whether or not there were any significant changes over time. Statistically significant improvements were seen in all outcome domains from pre-operative to one-year post-operative. All improvements met the threshold for achieving substantial clinical benefit as well as exceeding the minimum clinically important difference, and all improvements were maintained at the two-year post-operative time point. The present study showed that following the ULTRA guideline after elective RTSA can give statistically significant improvements in range of movement, pain score and patient-reported outcome at one-year post-operatively, which can be maintained up to two-years post-operatively.

Endoprosthesis vs. nail-cement spacer application for reconstruction after oncologic proximal humeral resection: is there a difference in functional outcome?

Background

The proximal humerus is a common site for primary malignant and benign aggressive bone tumors, necessitating wide resection and subsequent skeletal defect reconstruction. Various reconstruction options include osteoarticular allografts, autografts, endoprosthesis, nail-cement spacer, reverse shoulder arthroplasty, and allograft-prosthesis composites. However, there is no consensus on the optimal reconstruction method. This study aims to compare functional outcomes and complications between these two methods.

Methods

A total of 40 patients with proximal humerus tumors who underwent endoprosthesis or nail-cement spacer reconstruction between March 2012 and December 2020 were included. The mean follow-up in the study was 31.37 +/- 12 months. Demographic and clinical data were collected, and functional outcomes were assessed using the Musculoskeletal Tumor Society 93 scoring system and the Disabilities of the Arm, Shoulder, and Hand questionnaire. Complications and oncological outcomes were recorded.

Results

Both groups were similar in terms of demographic and clinical variables. Endoprosthesis reconstruction demonstrated significantly better active shoulder forward flexion compared to nail-cement spacer (45.8 vs. 25.2 degrees) (P = .015). Endoprosthesis group also exhibited greater active shoulder internal rotation (68.25 vs. 63.25 degrees) (P = .004). No statistically significant differences were observed in overall functional outcomes. Complications, including radial nerve palsy and infection, were comparable between groups, with one case of spacer loosening.

Conclusion

Both endoprosthesis and nail-cement spacer reconstruction provide comparable functional outcomes and complication rates following proximal humerus tumor resection. Nail-cement spacer offers a cost-effective alternative for patients in resource-constrained settings.

Preoperative diagnosis and rotator cuff status impact functional internal rotation following reverse shoulder arthroplasty

PURPOSE

This study aimed to evaluate whether functional internal rotation (fIR) following reverse shoulder arthroplasty (RSA) differs based on diagnosis of either: primary osteoarthritis (OA) with intact rotator cuff, massive irreparable rotator cuff tear (MICT) or cuff tear arthropathy (CTA).

METHODS

A retrospective review was carried out on RSAs performed by a single surgeon with the same implant over a 5-year period. Minimum 2-year follow-up was available in 235 patients; 139 (59.1%) were female, and the mean patient age was 72 ± 8 years. Additional clinical evaluation included the Subjective Shoulder Value and Constant score. Postoperative internal rotation was categorized as type I: hand to the buttock or hip; type II: hand to the lower lumbar region; or type III: smooth motion to at least the upper lumbar region. Type I was considered "nonfunctional" internal rotation, and type II and III were fIR.

RESULTS

Preoperatively, internal rotation was classified as type I in 60 patients (25.5%), type II in 114 (48.5%), and type III in 62 (26%). Postoperatively, internal rotation was classified as type I in 70 patients (30%), type II in 86 (36%), and type III in 79 (34%). Compared with preoperative status, fIR improved significantly in OA patients (P < .001), with 49 (52.6%) classified as type II or III postoperatively. In CTA patients, there was no significant change (P = .352). In patients with MICTs, there was a significant loss in fIR postoperatively (P = .003), with 25 patients (30.8%) deteriorating to type I after having either type II or III preoperatively, and only 5 patients (6.1%) improving to either type II or III.

CONCLUSIONS

Patients who undergo RSA for primary OA have a better chance of postoperative fIR improvement. A decrease in fIR is common after RSA for MICTs.

The effect of lateralization and distalization after Grammont-style reverse total shoulder arthroplasty

BACKGROUND

The purpose of this study was to evaluate the relationship between multiple radiographic measures of lateralization and distalization and clinical outcome scores after a reverse total shoulder arthroplasty (RTSA).

METHODS

We retrospectively evaluated all RTSAs performed by the senior author between January 1, 2007, and November 1, 2017. We then evaluated the visual analog scale for pain (VAS pain), Simple Shoulder Test (SST), and American Shoulder and Elbow Surgeons (ASES) scores and complication and reoperation rates at a minimum of 2-year follow-up. We measured preoperative and postoperative (2-week) radiographs for the lateralization shoulder angle (LSA), the distalization shoulder angle (DSA), lateral humeral offset, and the distance from the glenoid to the lateral aspect of the greater tuberosity. A multivariable analysis was performed to evaluate the effect of the postoperative radiographic measurements on final patient-reported outcomes (ASES scores, SST, and VAS pain).

RESULTS

The cohort included 216 shoulders from unique patients who had patient-reported outcome scores available at a minimum of 2-year follow-up (average, 4.0 ± 1.9 years) for a total follow-up rate of 70%. In the multivariable models, more lateralization (LSA) was associated with worse final ASES scores -0.52 (95% confidence interval [CI]: -0.88, -0.17; P = .004), and more distalization (DSA) was associated with better final ASES scores 0.40 (95% CI: 0.11, 0.69; P = .007). More lateralization (LSA) was associated with worse final SST scores -0.06 (95% CI: -0.11, -0.003; P = .039). Finally, greater distalization (DSA) was associated with lower final VAS pain scores, ratio = 0.98 (95% CI: 0.96, 1.00; P = .021).

CONCLUSIONS

Greater distalization and less lateralization are associated with better function and less pain after a Grammont-style RTSA. When using a Grammont-style implant, remaining consistent with Grammont's principles of implant placement will afford better final clinical outcomes.

Predictive factors influencing internal rotation following reverse total shoulder arthroplasty

BACKGROUND

Reverse total shoulder arthroplasty (RTSA) is increasingly used as a treatment modality for various pathologies. The purpose of this review is to identify preoperative risk factors associated with loss of internal rotation (IR) after RTSA.

METHODS

A systematic review was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Ovid MEDLINE, Ovid Embase, and Scopus were queried. The inclusion criteria were as follows: articles in English language, minimum 1-year follow-up postoperatively, study published after 2012, a minimum of 10 patients in a series, RTSA surgery for any indication, and explicitly reported IR. The exclusion criteria were as follows: articles whose full text was unavailable or that were unable to be translated to English language, a follow-up of less than 1 year, case reports or series of less than 10 cases, review articles, studies in which tendon transfers were performed at the time of surgery, procedures that were not RTSA, and studies in which the range of motion in IR was not reported.

RESULTS

The search yielded 3792 titles, and 1497 duplicate records were removed before screening. Ultimately, 16 studies met the inclusion criteria with a total of 5124 patients who underwent RTSA. Three studies found that poor preoperative functional IR served as a significant risk factor for poor postoperative IR. Eight studies addressed the impact of subscapularis, with 4 reporting no difference in IR based on subscapularis repair and 4 reporting significant improvements with subscapularis repair. Among studies with sufficient power, BMI was found to be inversely correlated with degree of IR after RTSA. Preoperative opioid use was found to negatively affect IR. Other studies showed that glenoid retroversion, component lateralization, and individualized component positioning affected postoperative IR.

CONCLUSIONS

This study found that preoperative IR, individualized implant version, preoperative opioid use, increased body mass index and increased glenoid lateralization were all found to have a significant impact on IR after RTSA. Studies that analyzed the impact of subscapularis repair reported conflicting results.

Internal rotation limitation is prevalent following modern reverse shoulder arthroplasty and negatively affects patients' subjective rating of the procedure

BACKGROUND

Although forward elevation, abduction, and external rotation are often successfully restored, internal rotation (IR) is frequently not satisfactorily recovered following reverse shoulder arthroplasty (RSA), affecting patients' ability to perform certain daily activities. This study examined the prevalence of limited IR in patients receiving modern RSA and its impact on clinical outcomes and patient satisfaction with their RSA.

METHODS

A cross-sectional study was conducted on patients who had undergone primary RSA using a modern RSA prosthesis with a minimum 1-year follow-up. Patients returned for a research visit where they were examined for range of motion and surveyed for patient-reported outcome measures (PROMs) and subjective rating of the success level of their RSA. Postoperative range of motion data were compared with the preoperative data. The relationship of postoperative IR with PROMs and patients' subjective rating of RSA was analyzed. Logistic regression was performed to identify factors affecting patients' subjective rating of RSA.

RESULTS

A total of 78 patients met the criteria and completed the study. A significant portion (59%) reported subjective IR limitations, and 41% had objective IR limitations. Comparison of preoperative and postoperative IR showed that 24% had worsened IR, whereas 33% improved. Limited IR was associated with lower patients' subjective rating of RSA and negatively affected PROMs, especially when the dominant side was operated on. Regression analysis showed that limited IR was the only independent determining factor that was significantly associated with a lower subjective rating of RSA.

DISCUSSION

Despite advancements in RSA design, limited IR remains a prevalent issue, significantly affecting patients' satisfaction and clinical outcomes. This study underscores the need for setting appropriate expectations regarding IR through patient education and focused efforts to improve IR limitations in RSA patients, particularly on the dominant side.

Modification of Humeral Component Results in Increased Impingement Free Range of Motion in a Reverse Shoulder Arthroplasty Model

Introduction

Shoulder arthroplasties have been demonstrated to provide reliable pain relief as well as functional benefits. The advent of the reverse shoulder arthroplasty allowed for expanded indications for shoulder replacement. Several studies comparing the outcomes of anatomic and reverse total shoulder arthroplasties have demonstrated decreased range of motion in the reverse arthroplasty cohort, especially in internal rotation. The authors hypothesized that slight modifications to the humeral component of a reverse shoulder arthroplasty could result in increased impingement free range of motion without significant sacrifices to stability.

Methods

A reverse shoulder arthroplasty model was fashioned to mimic a setting of anterior mechanical impingement after replacement. Sequential resections were taken from the anterior aspect of the polyethylene up to a resection of 10 mm. A solid modeling software was utilized to compare the experimental group to the control group with regard to impingement free motion. Finite element analysis was subsequently utilized to assess stability of the construct in comparison to the nonmodified polyethylene.

Results

Impingement free internal rotation increased minimally at 3 mm of resection but considerably at each further increase in resection. A resection of 10 mm resulted roughly 30% improvement in impingement free internal rotation. Instability in this model increased with modifications beyond 7 mm.

Conclusion

Slight alterations to the geometry of the humeral tray and polyethene components can result in improvements in impingement-free internal rotation without substantial increased instability in this model. Further work is needed to determine in vivo implications of modifications to the humeral tray and polyethylene.

Scapular motion during shoulder joint extension movement

A few reports on scapular motion during shoulder joint extension exist. Understanding the normal motion of shoulder joint extension may be useful in evaluating and treating patients with diminished or minimal shoulder joint extension. Therefore, this study aimed to identify scapular motion during shoulder joint extension movement in a sitting position. Shoulder joint extension movement in the sitting position were measured in 22 healthy adults (age, 25.8 ± 2.7 years). Shoulder joint extension, scapular upward rotation, anterior tilt, external rotation angles, and the acromion position were investigated using a three-dimensional motion analyzer. The difference from each value of 10° to 50° shoulder joint extension to each value of 0° shoulder joint extension were checked. The results were compared using multiple comparison method. In most participants, the scapula tilted posteriorly up to 30° of the shoulder joint extension and anteriorly after 30°. Scapular upward and external rotation continued to increase with shoulder extension. Furthermore, the acromion was displaced upward and backward. Thus, scapular posterior tilt is necessary for shoulder joint extension during the initial movement, followed by anterior tilt. The acromion may have been displaced posteriorly because of clavicular retraction, causing the scapula to tilt posteriorly. After 30° of shoulder joint extension, the scapular anterior tilt may have prevailed over the scapular posterior tilt.

Managing rotator cuff tear arthropathy: a role for cuff tear arthropathy hemiarthroplasty as well as reverse total shoulder arthroplasty

BACKGROUND

Disabling cuff tear arthropathy (CTA) is commonly managed with reverse shoulder arthroplasty (RSA). However, for patients with CTA having preserved active elevation, cuff tear arthropathy hemiarthroplasty (CTAH) may offer a cost-effective alternative that avoids the complications unique to RSA. We sought to determine the characteristics and outcomes of a series of patients with CTA managed with these procedures.

MATERIALS AND METHODS

We retrospectively reviewed 103 patients with CTA treated with shoulder arthroplasty, the type of which was determined by the patient's ability to actively elevate the arm. Outcome measures included the change in the Simple Shoulder Test (SST), the percent maximum improvement in SST (%MPI), and the percentage of patients exceeding the minimal clinically important difference for the change in SST and %MPI. Postoperative x-rays were evaluated to assess the positions of the center of rotation and the greater tuberosity for each implant.

RESULTS

Forty-four percent of the 103 patients were managed with CTAH while 56% were managed with RSA. Both arthroplasties resulted in clinically significant improvement. Patients having RSA improved from a mean preoperative SST score of 1.7 (interquartile range [IQR], 0.0-3.0) to a postoperative score of 6.3 (IQR, 2.3-10.0) (P < .01). Patients having CTAH improved from a preoperative SST score of 3.1 (IQR, 1.0-4.0) to a postoperative score of 7.6 (IQR, 5.0-10.) (P < .001). These improvements exceeded the minimal clinically important difference. Instability accounted for most of the RSA complications; however, it did not account for any CTAH complications. The postoperative position of the center of rotation and greater tuberosity on anteroposterior radiographs did not correlate with the clinical outcomes for either procedure.

CONCLUSION

For 103 patients with CTA, clinically significant improvement was achieved with appropriately indicated CTAH and RSA. In view of the lower cost of the CTAH implant, it may provide a cost-effective alternative to RSA for patients with retained active elevation.

Influence of lateralized versus medialized reverse shoulder arthroplasty design on external and internal rotation: a systematic review and meta-analysis

BACKGROUND

Restoration of external (ER) and internal rotation (IR) after Grammont-style reverse shoulder arthroplasty (RSA) is often unreliable. The purpose of this systematic review was to evaluate the influence of RSA medio-lateral offset and subscapularis repair on axial rotation after RSA.

METHODS

We conducted a systematic review of studies evaluating axial rotation (ER, IR, or both) after RSA with a defined implant design. Medio-lateral implant classification was adopted from Werthel et al. Meta-analysis was conducted using a random-effects model.

RESULTS

Thirty-two studies reporting 2,233 RSAs were included (mean patient age, 72.5 years; follow-up, 43 months; 64% female). The subscapularis was repaired in 91% (n=2,032) of shoulders and did not differ based on global implant lateralization (91% for both, P=0.602). On meta-analysis, globally lateralized implants achieved greater postoperative ER (40° [36°-44°] vs. 27° [22°-32°], P<0.001) and postoperative improvement in ER (20° [15°-26°] vs. 10° [5°-15°], P<0.001). Lateralized implants with subscapularis repair or medialized implants without subscapularis repair had significantly greater postoperative ER and postoperative improvement in ER compared to globally medialized implants with subscapularis repair (P<0.001 for both). Mean postoperative IR was reported in 56% (n=18) of studies and achieved the minimum necessary IR in 51% of lateralized (n=325, 5 cohorts) versus 36% (n=177, 5 cohorts) of medialized implants.

CONCLUSIONS

Lateralized RSA produces superior axial rotation compared to medialized RSA. Lateralized RSA with subscapularis repair and medialized RSA without subscapularis repair provide greater axial rotation compared to medialized RSA with subscapularis repair. Level of evidence: 2A.

Obesity is associated with improvement in functional outcome but lower internal rotation after reverse shoulder arthroplasty

Background

The role of obesity as an independent risk factor for increased complications following reverse shoulder arthroplasty (RSA) continues to generate debate. While no standardized body mass index (BMI) cutoff values for shoulder arthroplasty exist, many surgeons are concerned about the potential for poor outcomes and decreased range of motion (ROM) in patients with a high BMI. The purpose of this study was to compare functional outcomes in obese and nonobese patients preoperatively and at short-term follow-up after RSA.

Methods

A retrospective review was performed of a prospectively maintained, multicenter database of primary RSAs performed by 14 surgeons between 2015 and 2019 with minimum 2-year follow-up. A total of 245 patients met the study criteria, including 111 obese (BMI >30) and 134 nonobese (BMI <30) patients. Patient-reported outcomes (PROs) as well as ROM measurements were compared between the 2 groups.

Results

At baseline, obese patients had significantly lower American Shoulder and Elbow Surgeons (36.6 vs. 42.0, P = .014), Western Ontario Osteoarthritis of the Shoulder scores (33.1 vs. 37.8, P = .043), external rotation at 90° (19° vs. 28°, P = .007), internal rotation (IR) spinal level (L5 vs. L4, P = .002), and belly press strength (P = .003) compared to the nonobese cohort. There were no statistical differences in 2-year outcomes (PROs, ROM, and strength) other than a worse IR (spinal level) in the low BMI group (L4 vs. L3, P = .002). In linear regression analyses controlling for confounding variables, increasing BMI was negatively correlated with preoperative external rotation (B = -0.591, P = .034) and preoperative IR spinal level (B = 0.089, P = .002). Increasing BMI was not correlated with postoperative external rotation at 90° (B = 0.189, P = .490) but was associated with worse postoperative IR by spinal level (B = 0.066, P = .043).

Conclusions

Obese patients have greater restrictions in external and internal rotation as well as American Shoulder and Elbow Surgeons and Western Ontario Osteoarthritis of the Shoulder scores at baseline prior to RSA. However, there are no major differences in postoperative PROs or ROM measurements between obese and nonobese patients apart from a worse active IR by spinal level in the obese group (L4 vs. L3, P = .002). This study suggests that an RSA procedure does not need to be restricted solely based on BMI.

Glenoid lateralization and subscapularis repair are independent predictive factors of improved internal rotation after reverse shoulder arthroplasty

PURPOSE

Reverse shoulder arthroplasty (RSA) has shown improvement in clinical outcomes for various conditions, although some authors expressed concern about the restoration of active internal rotation (AIR). The current study assesses preoperative and intraoperative predictive factors of AIR in patients having a Grammont-style RSA with a minimum five year follow-up.

METHODS

We conducted a retrospective multicentric study, including patients operated on with a 155° Grammont-style RSA for cuff-related pathology or primary osteoarthritis with posterior subluxation or an associated cuff tear. Patients were clinically evaluated at a minimum of five year follow-up. Patients with previous surgery or those who had a tendon transfer with the RSA were excluded. Demographic parameters, BMI, preoperative notes, and operative reports were obtained from medical records. AIR was graded according to the constant score system from 0 to 10.

RESULTS

A total of 280 shoulders in 269 patients (mean age at surgery, 74.9 ± 5.9 years) met the inclusion criteria and were analyzed. The average follow-up was 8.1 years (range, 5-16 years). Overall, AIR increased from 4.2 (SD 2.5, range 0 to 10) preoperatively to 5.9 (SD 2.6, range 0 to 10) at final follow-up. At the last follow-up, AIR increased in 56% of cases, was unchanged in 26% and decreased in 18%. In 188 shoulders (67%), internal rotation was functional and allowed patients to reach the level of L3 or higher. Multivariable linear regression found the following preoperative clinical factors predictive of worse AIR after RSA: male gender (ß = -1.25 [-2.10; -0.40]; p = 0.0042) and higher values of BMI (ß = -0.085 [-0.17; -0.0065]; p = 0.048). Two surgical factors were associated with better AIR after RSA: glenoid lateralization with BIO-RSA technique (ß = 0.80 [0.043; 1.56]; p = 0.039) and subscapularis repair (ß = 1.16 [0.29; 2.02]; p = 0.0092).

CONCLUSIONS

With a mean of eight year follow-up (5 to 16 years), internal rotation was functional (≥ L3 level) in 67% of operated shoulders after Grammont-style RSA; however, two patients out of ten had decreased AIR after surgery. Male patients and those with higher BMIs had worse AIR, with glenoid lateralization (using the BIO-RSA technique) and subscapularis repair, as they are predictive of increased AIR after RSA.

LEVEL OF EVIDENCE

Case series, Level IV.

Influence of Lateralization and Distalization on Joint Function after Primary Reverse Total Shoulder Arthroplasty

The purpose of this study was to investigate how lateralization shoulder angle (LSA) and distalization shoulder angle (DSA) are related to clinical and kinematic outcomes after reverse total shoulder arthroplasty. Thirty-three patients were evaluated at least six months postoperatively. The Single Assessment Numeric Evaluation (SANE), Constant Murley Score (CMS), Simple Shoulder Test (SST), and Visual Analogue Scale (VAS) were used. Shoulder kinematics was evaluated with a stereophotogrammetric system. LSA and DSA inter-rater reliability was analysed through the interclass correlation coefficient (ICC). Stepwise forward linear regression analysis was conducted between LSA and DSA with clinical scales and kinematic measures, between which a correlation analysis was conducted. The inter-rater reliability for LSA (mean ICC = 0.93) and DSA (mean ICC = 0.97) results were good to excellent. Greater LSA values were associated with higher peaks of internal rotation (p = 0.012, R2 = 0.188) and range of motion (ROM) (p = 0.037, R2 = 0.133). SANE (p = 0.009), CMS (p = 0.031), and SST (0.026) were positively correlated to external rotation, while VAS (p = 0.020) was negatively related. Abduction peaks were positively related to CMS (p = 0.011) and SANE (p = 0.037), as well as abduction ROM (SANE, p = 0.031; CMS, p = 0.014).

Discordance between patient-reported and objectively measured internal rotation after reverse shoulder arthroplasty

BACKGROUND

Patient satisfaction after reverse shoulder arthroplasty (RSA) partly relies on restoring functional internal rotation (IR). Although postoperative assessment of IR includes objective appraisal by the surgeon and subjective report from the patient, these evaluations may not vary together uniformly. We assessed the relationship between objective, surgeon-reported assessments of IR and subjective, patient-reported ability to perform IR-related activities of daily living (IRADLs).

METHODS

Our institutional shoulder arthroplasty database was queried for patients undergoing primary RSA with a medialized-glenoid lateralized-humerus design between 2007-2019 and minimum 2-year follow-up. Patients who were wheelchair bound or had a preoperative diagnosis of infection, fracture, and tumor were excluded. Objective IR was measured to the highest vertebral level reached with the thumb. Subjective IR was reported based on patients' rating (normal, slightly difficult, very difficult, or unable) of their ability to perform 4 IRADLs (tuck in shirt with hand behind back, wash back or fasten bra, personal hygiene, and remove object from back pocket). Objective IR was assessed preoperatively and at latest follow-up and reported as median and interquartile ranges.

RESULTS

A total of 443 patients were included (52% female) at a mean follow-up of 4.4 ± 2.3 years. Objective IR improved pre- to postoperatively from L4-L5 (buttocks to L1-L3) to L1-L3 (L4-L5 to T8-T12) (P < .001). Preoperatively reported IRADLs of "very difficult" or "unable" significantly decreased postoperatively for all IRADLs (P ≤ .004) except those unable to perform personal hygiene (3.2% vs. 1.8%, P > .99). The proportions of patients who improved, maintained, and lost objective and subjective IR was similar between IRADLs; 14%-20% improved objective IR but lost or maintained subjective IR and 19%-21% lost or maintained the same objective IR but improved subjective IR depending on the specific IRADL assessed. When ability to perform IRADLs improved postoperatively, objective IR also increased (P < .001). In contrast, when subjective IRADLs worsened postoperatively, objective IR did not significantly worsen for 2 of 4 IRADLs assessed. When examining patients who reported no change in ability to perform IRADLs pre- vs. postoperatively, statistically significant increases in objective IR were found for 3 of 4 IRADLs assessed.

CONCLUSIONS

Objective improvement in IR parallels improvements in subjective functional gains uniformly. However, in patients with worse or equivalent IR, the ability to perform IRADLs postoperatively does not uniformly correlate with objective IR. When attempting to elucidate how surgeons can ensure patients will have sufficient IR after RSA, future investigations may need to use patient-reported ability to perform IRADLs as the primary outcome measure rather than objective measures of IR.

Latissimus Dorsi and Teres major tendon transfer increases internal rotation torque following lateralized reverse shoulder arthroplasty with subscapularis insufficiency

INTRODUCTION

Limitation of active Internal Rotation (IR) following Reverse Shoulder Arthroplasty (RSA) in patients with massive Rotator Cuff Tears (mRCTs) with subscapularis insufficiency remains a challenge. Recently, RSA with Latissimus dorsi and Teres major (LDTM) transfer in patients with limited active IR has been demonstrated as a reliable treatment option. The purpose of this study was to biomechanically compare the IR torque following LDTM transfer with RSA in mRCT with subscapularis insufficiency to RSA without tendon transfer.

METHODS

Eight cadaveric shoulders were tested (mean age: 64.5 ± 1.9 years) using a custom shoulder testing system that permits loading conditions of mRCT with subscapularis insufficiency. Two conditions were tested and compared. The first condition was RSA alone and the second condition was RSA with LDTM transfer. RSA with a medialized glenoid and lateralized humerus design was used for all specimens. The specimens were tested at 0°, 20° and 40° abduction at three different muscle loads: baseline, double, and triple, while the Teres minor and deltoid loads were kept constant. IR torque was measured with a torque wrench at 0°, 20°, and 40° abduction and 60° and 45° IR positions. Force required for anterior dislocation was measured at 20° abduction and 10° IR position.

RESULTS

RSA with LDTM transfer had significantly higher IR torque at all abductions and muscle loading compared with RSA without transfer (average at all positions; RSA without transfer: 0.80 ± 0.02 Nm, LDTM transfer for all loads: 1.43 ± 0.10 Nm). RSA with LDTM transfer (91.4 ± 3.9 N) needed higher force for anterior dislocation compared to RSA alone (89.4 ± 4.1 N), but there was no significant difference.

CONCLUSION

LDTM transfer with RSA increases IR torque compared to RSA without tendon transfer in a cadaveric model. LDTM transfer with RSA may be a reliable treatment option for patients with mRCT and subscapularis insufficiency who are expected to have limited active IR following RSA.

Do Magnets Have the Potential to Serve as a Stabilizer for the Shoulder Joint in Massive Rotator Cuff Tears?: A Biomechanical Cadaveric Study

Background

Disruption of the rotator cuff muscles compromises concavity compression force, which leads to superior migration of the humeral head and loss of stability. A novel idea of using the magnetic force to achieve shoulder stabilization in massive rotator cuff tears (MRCTs) was considered because the magnets can stabilize two separate entities with an attraction force. This study aimed to investigate the biomechanical effect of the magnetic force on shoulder stabilization in MRCTs.

Methods

Seven fresh frozen cadaveric specimens were used with a customized shoulder testing system. Three testing conditions were set up: condition 1, intact rotator cuff without magnets; condition 2, an MRCT without magnets; condition 3, an MRCT with magnets. For each condition, anterior-posterior translation, superior translation, superior migration, and subacromial contact pressure were measured at 0°, 30°, and 60° of abduction. The abduction capability of condition 2 was compared with that of condition 3.

Results

The anterior-posterior and superior translations increased in condition 2; however, they decreased compared to condition 2 when the magnets were applied (condition 3) in multiple test positions and loadings (p < 0.05). Abduction capability improved significantly in condition 3 compared with that in condition 2, even for less deltoid loading (p < 0.05).

Conclusions

The magnet biomechanically played a positive role in stabilizing the shoulder joint and enabled abduction with less deltoid force in MRCTs. However, to ensure that the magnet is clinically applicable as a stabilizer for the shoulder joint, it is necessary to thoroughly verify its safety in the human body and to conduct further research on technical challenges.

High and low performers in internal rotation after reverse total shoulder arthroplasty: a biplane fluoroscopic study

BACKGROUND

Internal rotation in adduction is often limited after reverse total shoulder arthroplasty (rTSA), but the origins of this functional deficit are unclear. Few studies have directly compared individuals who can and cannot perform internal rotation in adduction. Little data on underlying 3D humerothoracic, scapulothoracic, and glenohumeral joint relationships in these patients are available.

METHODS

Individuals >1-year postoperative to rTSA were imaged with biplane fluoroscopy in resting neutral and internal rotation in adduction poses. Subjects could either perform internal rotation in adduction with their hand at T12 or higher (high, N = 7), or below the hip pocket (low, N = 8). Demographics, the American Shoulder and Elbow Surgeons score, Simple Shoulder Test, and scapular notching grade were recorded. Joint orientation angles were derived from model-based markerless tracking of the scapula and humerus relative to the torso. The 3D implant models were aligned to preoperative computed tomography models to evaluate bone-implant impingement.

RESULTS

The Simple Shoulder Test was highest in the high group (11 ± 1 vs. 9 ± 2, P = .019). Two subjects per group had scapular notching (grades 1 and 2), and 3 high group and 4 low group subjects had impingement below the glenoid. In the neutral pose, the scapula had 7° more upward rotation in the high group (P = .100), and the low group demonstrated 9° more posterior tilt (P = .017) and 14° more glenohumeral elevation (P = .047). In the internal rotation pose, axial rotation was >45° higher in the high group (P ≤ .008) and the low group again had 11° more glenohumeral elevation (P = .058). Large rotational differences within subject groups arose from a combination of differences in the resting neutral and maximum internal rotation in adduction poses, not only the terminal arm position.

CONCLUSIONS

Individuals who were able to perform high internal rotation in adduction after rTSA demonstrated differences in joint orientation and anatomic biases versus patients with low internal rotation. The high rotation group had 7° more resting scapular upward rotation and used a 15°-30° change in scapular tilt to perform internal rotation in adduction versus patients in the low group. The combination of altered resting scapular posture and restricted scapulothoracic range of motion could prohibit glenohumeral rotation required to reach internal rotation in adduction. In addition, inter-patient variation in humeral torsion may contribute substantially to postoperative internal rotation differences. These data point toward modifiable implant design and placement factors, as well as foci for physical therapy to strengthen and mobilize the scapula and glenohumeral joint in response to rTSA surgery.

Does improved external rotation following reverse shoulder arthroplasty impact clinical outcomes in patients with rotator cuff pathology and external rotation less than 0°?

BACKGROUND

The purpose of this study was to (1) evaluate whether improved external rotation (ER) in patients with preoperative ER <0° impacts their clinical outcomes following reverse shoulder arthroplasty (RSA) for rotator cuff (RC) pathology and (2) describe the differences in preoperative factors and postoperative outcomes in this patient population. Our hypothesis was that clinical outcomes would not be affected by improvement in ER using a lateralized glenosphere design.

METHODS

We retrospectively reviewed 55 patients with preoperative ER <0° who underwent primary RSA for RC pathology with lateralized glenosphere. Pre- and postoperative physician-reported ER was blindly measured using a videographic review of patients externally rotating their arm at the side. Patients were evaluated using 5 different patient-reported outcome score thresholds, measured at 12 months postoperatively: (1) minimal clinically important difference (MCID) for American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) scores (ie, ≥20-point increase); (2) MCID for Simple Shoulder Test (SST) scores (≥2.4-point increase); (3) visual analog scale (VAS) for pain score >0; (4) mean ASES score (≥75); and (5) mean SST score (≥6.8), each of which was used to stratify the patients into 2 groups-greater than or equal to vs. less than the threshold. This resulted in 5 different evaluations comparing the 2 groups for any difference in postoperative ER or preoperative factors, including Hamada and Goutallier scores.

RESULTS

Regardless of the measured outcome, there was no difference in either postoperative physician- or patient-reported ER between patients who achieved scores higher or lower than the thresholds. Both Hamada and Goutallier score distributions were not different between groups across all the evaluated outcomes. Patients who achieved the MCID for ASES had worse preoperative VAS pain (7 vs. 4, P = .011) and SST (1 vs. 3, P = .020) scores. Across all outcome thresholds, except MCID for SST, pain reduction (ΔVAS) was significantly more pronounced in patients exceeding the thresholds. Improved forward flexion rather than ER was observed in those who achieved the ASES (160° vs. 80°, P = .020) and SST MCIDs (150° vs. 90°, P = .037). Finally, patients who exceeded the thresholds experienced higher satisfaction rates.

CONCLUSION

Improvement in ER does not appear to impact patient-reported outcome measures, including ASES and SST in patients with preoperative ER <0° undergoing RSA with a lateralized glenosphere. Patients with more severe pain and worse function at baseline experience less postoperative pain and clinically significant improvement in their reported outcomes.

A pilot-study focusing on internal rotation after reverse total shoulder arthroplasty using the Activities of Daily Living which require Internal Rotation (ADLIR) score

Background

Loss of internal rotation remains an issue after reverse total shoulder arthroplasty (RTSA). Our goal is to define the expected functional internal rotation after RTSA using the Activities of Daily Living which require Internal Rotation (ADLIR) score in a homogenous population of patients treated with RTSA.

Methods

35 patients with a minimum follow-up of two years after RTSA were evaluated using the ADLIR and Constant-Murley questionnaires. A correlation between the ADLIR and Constant score was investigated and the internal validity of the ADLIR score used in a RTSA patient population was measured using Cronbach's alpha coefficient. The impact of internal rotation on the total rotational arc of motion was defined.

Results

Excellent results were recorded for both the Constant score (79 ± 18) and ADLIR score (88 ± 16). Pearson's correlation coefficient was r = 0,84 (p-value <0,001). The ADLIR score showed a high reliability for all questions.

Conclusions

The ADLIR score has proven to be a useful addition in the post-operative evaluation of patients treated with RTSA. Further studies are needed to investigate the evolution of the ADLIR score from pre- to postoperatively in order to determine the clinical and predictive value of this score.

Level of evidence

Level IV - Observational study.

The clinical outcome of physiotherapy after reversed shoulder arthroplasty: a systematic review

PURPOSE

The purpose of this systematic review was to analyze the current literature on the clinical outcomes of physiotherapy (PT) program after reversed total shoulder arthroplasty (rTSA) and to summarize the improvements in this population.

METHODS

A search was performed in four databases (MEDLINE, Embase, PubMed, Google Scholar) from its inception to 30 April 2020. Data were extracted to describe the study design and rehab programs. The quality of evidence was assessed as high, moderate, and low-level according to the Evaluation of Quality of an Intervention Study critical appraisal criteria.

RESULTS

There were 22 eligible studies including two randomized controlled trials, four prospective cohort studies, 10 retrospective reviews, five case-series, and one case-control study, with the sample sizes ranging from 9 to 474 patients followed for 1-10 years. All studies indicated substantial improvement in patients after PT program in terms of functional outcomes and forward flexion.

CONCLUSIONS

High-quality RCTs are required to provide more conclusive results. We identified substantial variation in the post-operative PT programs except for the progressive mobilization strategy and the common management following surgery to increase the soft tissue healing within 4-6 weeks.Implications for RehabilitationThe reverse shoulder arthroplasty (rTSA) has been widely utilized for patients with rotator cuff arthropathy, primary arthritis, and proximal fractures.A successful outcome of rTSA is not only depending on the surgical management, but also depended on physiotherapy (PT) programs.Our systematic review concluded that a 12-week PT program starting with immobilization for 4-6 weeks, followed by 3-4 phases PT exercises including PROM, AAROM, AROM, and strength training was recommended as common management for patients received rTSA.Due to the huge variation in the included studies, the evidence of PT protocol in our study was not sufficient to summarize the better clinical practice suggestions regarding rTSA rehabilitation.

Inlay versus onlay humeral design for reverse shoulder arthroplasty: a systematic review and meta-analysis

BACKGROUND

Since the introduction of the Grammont-style reverse total shoulder arthroplasty, the humeral stem design has been modified with improved clinical outcomes. Two distinct humeral designs have been used extensively: the inlay design, in which the humeral tray is seated within the metaphysis, and the onlay design, in which the humeral tray sits on the metaphysis at the level of the humeral neck cut. The purpose of this systematic review was to determine whether there are differences in clinical outcomes and complication rates between these designs.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were used to perform this systematic review. A search of MEDLINE, PubMed, and Embase was performed to identify all studies comparing the clinical results of both humeral designs. Primary outcomes included patient-reported outcome measures, shoulder range of motion, and incidence of complications.

RESULTS

From the 156 identified publications, 12 studies were included in the final review. A total of 1447 patients were included, with a minimum follow-up period of 12 months. At final follow-up, both implants demonstrated significant improvements in comparison to preoperative baseline. On comparison of the inlay vs. onlay groups, the American Shoulder and Elbow Surgeons score was higher in the inlay group (mean difference, 2.53 [95% confidence interval, 0.27-4.78]; P = .03). Postoperative motion, even if statistically greater in the onlay group (differences of 5° in forward flexion [P < .001], 3° in abduction [P = .003], and 4° in external rotation [P < .001]), was not clinically different. On comparison of complications, the inlay group showed more instances of scapular notching (93 of 322 patients vs. 70 of 415 patients; odds ratio, 0.35; P < .001) but fewer scapular spine fractures (26 of 727 patients vs. 21 of 559 patients, P = .09).

DISCUSSION

Inlay and onlay humeral tray designs in reverse total shoulder arthroplasty demonstrate similar clinical improvements postoperatively. Onlay implants have a low rate of scapular notching but a higher rate of scapular spine fracture. Understanding the strengths and weaknesses of the 2 humeral tray designs is important to provide surgeons with options to tailor surgical plans for high-risk patients.

Outcomes and complications of primary reverse shoulder arthroplasty with minimum of 2 years' follow-up: a systematic review and meta-analysis

BACKGROUND

Primary reverse shoulder arthroplasty (rTSA) is an effective treatment option for reducing pain and improving function for patients with rotator cuff tear arthropathy, irreparable rotator cuff tears, glenoid deformity, and other challenging clinical scenarios, including fracture sequelae and revision shoulder arthroplasty. There has been a wide range of reported outcomes and postoperative complication rates reported in the literature. The purpose of this systematic review and meta-analysis is to provide an updated review of the clinical outcomes and complication rates following primary rTSA.

METHODS

A systematic review and meta-analysis was performed to evaluate outcomes and complications following primary rTSA according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Demographics, range of motion, patient-reported outcome measures (American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form [ASES] and Constant scores), number of complications, and revisions were extracted, recorded, and analyzed from the included articles.

RESULTS

Of the 1415 studies screened, 52 studies met the inclusion criteria comprising a total of 5824 shoulders. The mean age at the time of surgery was 72 years (range: 34-93), and the mean follow-up was 3.9 years (range: 2-16). Patients demonstrated a mean improvement of 56° in active flexion, 50° in active abduction, and 14° in active external rotation. Regarding functional outcome scores, rTSA patients demonstrated a mean clinically significant improvement of 37 in Constant score (minimal clinically important difference [MCID] = 5.7) and ASES score (42.0; MCID = 13.6). The overall complication rate for rTSA was 9.4% and revision rate of 2.6%. Complications were further subdivided into major medical complications (0.07%), shoulder- or surgical-related complications (5.3%), and infections (1.2%). The most frequently reported shoulder- or surgical-related complications were scapular notching (14.4%), periprosthetic fracture (0.8%), glenoid loosening (0.7%), and prosthetic dislocation (0.7%).

DISCUSSION

Primary rTSA is a safe and reliable procedure with low complication, revision, infection, and scapular notching rates. Additionally, patients demonstrated clinically significant improvements in both range of motion and clinical outcome scores.

Factors associated with improvement or loss of internal rotation after reverse shoulder arthroplasty

BACKGROUND

Internal rotation (IR) with reverse total shoulder arthroplasty (rTSA) can be unpredictable. Identifying the factors associated with loss of or improved IR could aid preoperative patient counseling. This study quantifies the change in IR experienced by rTSA patients with nonfracture indications and identifies the patient, implant, and operative factors associated with IR loss or gain at 2-year minimum follow-up.

METHODS

A total of 1978 primary rTSA patients were analyzed from an international database of a single rTSA prosthesis to quantify IR at 2 years' minimum follow-up. rTSA patients were divided into 2 cohorts based on their preoperative IR score, with group 1 patients having less active IR as defined by a preoperative IR score ≤3 and group 2 patients having greater active IR as defined by a preoperative IR score ≥4 (ie, L5 or higher). For both group 1 and 2 patients, univariate and multivariate analyses were performed to quantify the risk factors associated with IR loss after rTSA.

RESULTS

Overall, 58.9% of rTSA patients experienced IR improvement and 17.0% lost IR after rTSA. The occurrence of IR loss or gain was dependent on preoperative IR score, as 73.2% of group 1 patients improved IR and only 40.1% of group 2 patients improved IR, whereas 31.0% of group 2 patients lost IR and only 6.3% of group 1 patients lost IR after rTSA. Numerous risk factors for IR loss were identified. For group 1 patients, male sex (P = .004, odds ratio [OR] = 2.056), tobacco usage (P = .004, OR = 0.348), larger humeral stem diameter (P = .008, OR = 0.852), and not having subscapularis repaired (P = .002, OR = 2.654) were significant risk factors for IR loss. For group 2 patients, male sex (P = .005, OR = 1.656), higher body mass index (P = .002, OR = 0.946), a diagnosis other than osteoarthritis (P < .001, OR = 2.189), nonaugmented baseplate usage (P < .001, OR = 2.116), and not having subscapularis repaired (P < .001, OR = 3.052) were significant risk factors for IR loss.

CONCLUSION

The majority of patients improve IR after rTSA in the nonfracture setting. rTSA patients with substantial IR prior to surgery had a greater probability for losing IR compared to patients with poor preoperative IR. Numerous risk factors for IR loss were identified; these risk factors are useful for counseling patients considering rTSA, as some patients are more likely to lose IR than others.

Restoration of active internal rotation following reverse shoulder arthroplasty: anterior latissimus dorsi and teres major combined transfer

BACKGROUND

Reverse shoulder arthroplasty (RSA) for irreparable massive rotator cuff tear (mRCT) and cuff tear arthropathy (CTA) demonstrates satisfactory clinical outcomes. However, many studies have reported no significant improvements in internal and external rotation. To our knowledge, there have been no studies on new attempts to restore active internal rotation following RSA. The purpose of this study was to compare RSA alone and RSA with anterior latissimus dorsi and teres major (aLDTM) tendon transfer in patients with CTA and mRCT with combined loss of active elevation and internal rotation (CLEIR).

METHODS

This retrospective cohort study included patients who underwent RSA with a lateralized design and had CLEIR between October 2014 and January 2019. Two groups were classified: patients who underwent RSA alone (group R, n = 36) and patients who underwent RSA with aLDTM tendon transfer (group T, n = 24). Clinical outcomes, including the visual analog scale score, Constant score, American Shoulder and Elbow Surgeons score, active range of motion, score for activities of daily living requiring active internal rotation (ADLIR), and ability to perform toileting activity, were compared. Moreover, radiologic outcomes and complications were compared.

RESULTS

The mean follow-up period was 36.8 ± 11.6 months (range, 24-67 months). Both group R and group T showed significant improvements in clinical scores and active range of motion preoperatively and postoperatively. In group T, the Constant score (65.2 ± 7.5 vs. 58.1 ± 12.3, P = .008), ADLIR score (26.1 ± 3.1 vs. 20.3 ± 5.0, P < .001), internal rotation level with the arm behind the back (P < .001), and subscapularis-specific physical examination findings (P < .001) were significantly better than in group R. However, no significant difference in the American Shoulder and Elbow Surgeons score, forward flexion, and external rotation at 0° and 90° of abduction were found at final follow-up. Transient axillary nerve palsy was found in 2 patients in group T. However, there were no significant differences in complication rates between 2 groups.

CONCLUSION

Lateralized RSA with aLDTM tendon transfer for patients with CTA and mRCT with CLEIR restored shoulder function and improved clinical outcomes, especially the ability to perform ADLIR and toileting activity.

Extension of the shoulder is essential for functional internal rotation after reverse total shoulder arthroplasty

BACKGROUND

Disabling loss of functional internal rotation (fIR) after reverse total shoulder arthroplasty (RTSA) is frequent but not well understood. This study tested the hypothesis that limitation of fIR after RTSA is not primarily related to a deficit in internal rotation.

METHODS

Fifty patients (mean age at RTSA, 74 ± 11.7 years) who were consecutively seen at a yearly follow-up visit at 1-10 years (median, 4 years) after RTSA were prospectively examined with special attention to fIR. Patients with axillary nerve or deltoid dysfunction were excluded. Relative (age- and sex-adjusted) Constant-Murley scores (CSs) and Subjective Shoulder Values were assessed preoperatively and at final follow-up. In addition, active extension and 4 postoperative activities of daily living (ADLs) requiring fIR were tested at follow-up. Rotator cuff fatty infiltration and notching were evaluated radiographically. For analysis, patients were divided into a group with poor fIR (fIR-, n = 19), defined as ≤2 internal-rotation points in the CS, and a group with good fIR (fIR+, n = 31), defined as ≥4 internal-rotation points in the CS.

RESULTS

Active extension of the contralateral shoulders was comparable in the fIR- group (mean, 60.3° [standard deviation (SD), 11.2°]) and fIR+ group (66.1° [SD, 14.2°]). Postoperatively, a difference in active extension between the unaffected and operated sides was present in both groups and averaged 16° (55° [SD, 14.3°] in fIR+ group and 39.1° [SD, 10.8°] in fIR- group; P < .001). No patient in the fIR+ group had active extension < 40° (range, 40°-85°). Shoulders with extension ≥ 40° but unsatisfactory fIR had restricted passive internal rotation in extension. The ability to perform ADLs behind the back correlated better with shoulder extension than with so-called fIR measurements in the CS.

CONCLUSION

Functional internal rotation after RTSA requires at least 40° of shoulder extension. If fIR is unsatisfactory despite 40° of extension, passive restriction of internal rotation in full extension is the limiting factor. It is crucial to preserve or restore active shoulder extension to allow ADLs involving internal rotation.

Using machine learning to predict internal rotation after anatomic and reverse total shoulder arthroplasty

BACKGROUND

Improvement in internal rotation (IR) after anatomic (aTSA) and reverse (rTSA) total shoulder arthroplasty is difficult to predict, with rTSA patients experiencing greater variability and more limited IR improvements than aTSA patients. The purpose of this study is to quantify and compare the IR score for aTSA and rTSA patients and create supervised machine learning that predicts IR after aTSA and rTSA at multiple postoperative time points.

METHODS

Clinical data from 2270 aTSA and 4198 rTSA patients were analyzed using 3 supervised machine learning techniques to create predictive models for internal rotation as measured by the IR score at 6 postoperative time points. Predictions were performed using the full input feature set and 2 minimal input feature sets. The mean absolute error (MAE) quantified the difference between actual and predicted IR scores for each model at each time point. The predictive accuracy of the XGBoost algorithm was also quantified by its ability to distinguish which patients would achieve clinical improvement greater than the minimal clinically important difference (MCID) and substantial clinical benefit (SCB) patient satisfaction thresholds for IR score at 2-3 years after surgery.

RESULTS

rTSA patients had significantly lower mean IR scores and significantly less mean IR score improvement than aTSA patients at each postoperative time point. Both aTSA and rTSA patients experienced significant improvements in their ability to perform activities of daily living (ADLs); however, aTSA patients were significantly more likely to perform these ADLs. Using a minimal feature set of preoperative inputs, our machine learning algorithms had equivalent accuracy when predicting IR score for both aTSA (0.92-1.18 MAE) and rTSA (1.03-1.25 MAE) from 3 months to >5 years after surgery. Furthermore, these predictive algorithms identified with 90% accuracy for aTSA and 85% accuracy for rTSA which patients will achieve MCID IR score improvement and predicted with 85% accuracy for aTSA patients and 77% accuracy for rTSA which patients will achieve SCB IR score improvement at 2-3 years after surgery.

DISCUSSION

Our machine learning study demonstrates that active internal rotation can be accurately predicted after aTSA and rTSA at multiple postoperative time points using a minimal feature set of preoperative inputs. These predictive algorithms accurately identified which patients will, and will not, achieve clinical improvement in IR score that exceeds the MCID and SCB patient satisfaction thresholds.

A comprehensive evaluation of the association of radiographic measures of lateralization on clinical outcomes following reverse total shoulder arthroplasty

BACKGROUND

Although reverse total shoulder arthroplasty (RTSA) has excellent reported outcomes and satisfaction, patients often have postoperative limitations in range of motion (ROM), specifically internal rotation. Increased lateralization is thought to improve ROM following RTSA. The purpose of this study was to evaluate the association between radiographic measurements of lateralization and postoperative ROM and clinical outcome scores following RTSA. The authors hypothesized that increased radiographic lateralization would be associated with improved postoperative ROM, specifically internal rotation, but have no significant association with clinical outcome scores.

METHODS

Patients who underwent RTSA with a 135° neck-shaft angle prosthesis and minimum 2-year clinical and radiographic follow-up were included and retrospectively reviewed. Postoperative radiographs were evaluated for several lateralization measurements including the lateralization shoulder angle (LSA), distance from the lateral border of the acromion to the lateral portion of the glenosphere, distance from the glenoid to the most lateral aspect of the greater tuberosity, and the distance from the lateral aspect of the acromion to the most lateral aspect of the greater tuberosity. Linear regression analyses were used to evaluate the independent association of each radiographic measurement of lateralization on forward flexion, external rotation, internal rotation, and the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) index score at 2 years postoperation. Receiver operating characteristic (ROC) curves were constructed to identify significant thresholds of each radiographic lateralization measurement.

RESULTS

A total of 203 patients were included. For internal rotation, a greater LSA (P = .007), shorter acromion to glenosphere distance (meaning more glenoid lateralization) (P = .005), and a greater acromion to greater tuberosity distance (with the tuberosity more lateral to the acromion) (P = .021) were associated with improved internal rotation. Overall, ROC analysis demonstrated very little significant data, the most notable of which was the LSA, which had a significant cutoff of 82° (sensitivity 57%, specificity 68%, P = .012).

CONCLUSION

Of the numerous radiographic measures of lateralization after RTSA, the LSA is the most significantly associated with outcomes, including improved internal rotation and a decrease in forward flexion and ASES score. The clinical significance of these statistically significant findings requires further study, as the observed associations were for very small changes that may not represent clinical significance.

Relationship between postoperative integrity of subscapularis tendon and functional outcome in reverse shoulder arthroplasty

HYPOTHESIS AND BACKGROUND

The role of the subscapularis in reverse shoulder arthroplasty (RSA) remains controversial. Studies have shown that subscapularis repair has no significant influence on the functional outcomes of patients. However, few studies have assessed the postoperative integrity of the subscapularis tendon after RSA. The aims of this study were to investigate the postoperative healing of the subscapularis after RSA via ultrasound and to evaluate the relationship between tendon integrity and functional outcomes. We hypothesized that subjects with a healed subscapularis after RSA would have higher Constant scores and better internal rotation (IR) than those without a healed subscapularis.

METHODS

This was a retrospective review of all patients who underwent primary RSA with subscapularis tenotomy repair performed by a single surgeon with a minimum 2-year follow-up period. The inclusion criteria were (1) primary RSA and (2) complete intraoperative repair of the subscapularis tenotomy if the tendon was amenable to repair. The total Constant score and active and passive range of motion were measured preoperatively and at every postoperative visit. IR was further subcategorized into 3 functional types (type I, buttock or sacrum; type II, lumbar region; and type III, T12 or higher). The integrity of the subscapularis on ultrasound at 2 years was reported using the Sugaya classification. The correlation between subscapularis integrity and functional outcomes including functional IR was evaluated.

RESULTS

A total of 86 patients (mean age, 73 ± 7.4 years; age range, 50-89 years) were evaluated. The mean postoperative Constant score for all patients significantly improved from 38 points to 72 points (P < .001) at last follow-up (mean, 3.3 years). There was significant improvement in all Constant score functional subscales and in terms of range of motion. The rate of sonographic healing of the subscapularis was 52.6%. There was no difference in Constant scores between "intact" and "failed" tendon repairs; however, intact tendons demonstrated significantly better IR with no difference in external rotation (P < .01).

CONCLUSION

The healing rate of the subscapularis following RSA was only 52.6%. IR function in patients with an intact subscapularis at 2 years after RSA was significantly better than in patients with failed or absent tendon repairs. Primary repair of reparable subscapularis tendons during RSA should be strongly considered.

Does Humeral Component Version Affect Range of Motion and Clinical Outcomes in Reverse Total Shoulder Arthroplasty? A Systematic Review

BACKGROUND

Prosthesis selection, design, and placement in reverse total shoulder arthroplasty (RTSA) affect post-operative results. The aim of this systematic review was to evaluate the influence of the humeral stem version and prosthesis design (inlay vs. onlay) on shoulder function following RTSA.

METHODS

A systematic review of the literature on post-operative range of motion (ROM) and functional scores following RTSA with specifically known humeral stem implantations was performed using MEDLINE, Pubmed, and Embase databases, and the Cochrane Library. Functional scores included were Constant scores (CSs) and/or American Shoulder and Elbow Surgeons (ASES) scores. The patients were organised into three separate groups based on the implanted version of their humeral stem: (1) less than 20° of retroversion, (2) 20° of retroversion, and (3) greater than 20° of retroversion.

RESULTS

Data from 14 studies and a total of 1221 shoulders were eligible for analysis. Patients with a humeral stem implanted at 20° of retroversion had similar post-operative mean ASES (75.8 points) and absolute CS (68.1 points) compared to the group with humeral stems implanted at less than 20° of retroversion (76 points and 62.5 points; p = 0.956 and p = 0.153) and those implanted at more than 20° of retroversion (73.3 points; p = 0.682). Subjects with humeral stem retroversion at greater than 20° tended towards greater active forward elevation and external rotation compared with the group at 20° of retroversion (p = 0.462) and those with less than 20° of retroversion (p = 0.192). Patients with an onlay-type RTSA showed statistically significantly higher mean post-operative internal rotation compared to patients with inlay-type RTSA designs (p = 0.048). Other functional scores and forward elevation results favoured the onlay-types, but greater external rotation was seen in inlay-type RTSA designs (p = 0.382).

CONCLUSIONS

Humeral stem implantation in RTSA at 20° of retroversion and greater appears to be associated with higher post-operative outcome scores and a greater range of motion when compared with a retroversion of less than 20°. Within these studies, onlay-type RTSA designs were associated with greater forward elevation but less external rotation when compared to inlay-type designs. However, none of the differences in outcome scores and range of motion between the humeral version groups were statistically significant.

Glenoid lateralization influences active internal rotation after reverse shoulder arthroplasty

BACKGROUND

Improvement in internal rotation (IR) is not reliably achieved after reverse total shoulder arthroplasty (RSA). The purpose of this study was to evaluate the relationship between postoperative IR and glenoid-sided lateralization following RSA in an implant using metallic lateralization.

METHODS

A multicenter retrospective study of RSAs with minimum 1-year clinical follow-up was performed. Patients were stratified based on the amount of glenoid-sided implant lateralization into 4 groups: 0-2 mm (n = 57), 4 mm (n =238), 6 mm (n = 95), and 8 mm (n = 65). The primary study outcome was active IR at a minimum of 1 year postoperatively, measured both by spinal level and in degrees with the shoulder abducted to 90°. Secondary outcomes were active forward flexion and external rotation, belly press strength, and subjective patient-reported outcome (PRO) measures. Comparisons were made with 1-way analyses of variance. Linear regression analyses evaluating for the association of glenoid lateralization with active IR were also performed to control for additional confounders, including demographics and other implant variables such as glenosphere diameter, humeral lateralization, humeral version, and whether the subscapularis was repaired.

RESULTS

A total of 455 patients were included in the study. The mean age was 69 years, and 48% of patients were male. IR differences varied by the method of measurement (spinal level vs. IR in degrees with arm abducted). Overall, patients with 8 mm of glenoid lateralization had significantly improved IR compared with all other lateralization groups. Patients with 6 mm of glenoid lateralization had significantly improved IR compared with the 0-2- and 4-mm groups. There were no significant differences in the secondary outcomes or PROs between lateralization groups. In the regression analysis, glenoid lateralization was the only implant-related variable that was significantly associated with improved IR for both measurement methods. Glenosphere diameter and humeral version were both significantly associated with IR measured in degrees with the arm abducted but not spinal level.

CONCLUSIONS

For the studied implant system, glenoid lateralization of 6-8 mm was associated with improved active IR at 1 year compared to patients with less glenoid lateralization with no significant differences in active forward flexion, external rotation, or PROs. In a multivariable analysis, increased humeral retroversion was associated with increased IR at 90° and increasing glenosphere diameter was associated with decreased IR at 90°, whereas BMI, subscapularis repair, and humeral lateralization did not significantly affect active IR.

Comparing patient-reported outcome measures and physical examination for internal rotation in patients undergoing reverse shoulder arthroplasty: does surgery alter patients' perception of function?

BACKGROUND

The purpose of this study was to evaluate how patients treated with reverse shoulder arthroplasty (RSA) achieve internal rotation (IR) using video assessment and to compare this to patient-reported outcome measures (PROMs).

METHODS

We reviewed 215 preoperative and 657 postoperative videos (3-78 months) for 215 patients who underwent primary RSA, performing IR using the modified vertebral level method. Their functional motion pattern was then grouped into 3 types: type I, could not reach behind their back; type II, able to reach to at least waist level, with assistance; and type III, able to reach to a minimum of waist level in an uninterrupted fashion. Patients completed functional questions (put on a coat, wash back, tuck in a shirt, and manage toileting) and a diagram of perceived IR. Patients' functional motion types were compared to PROM answers. Pre- and postoperative scores were also compared to assess the effect of surgery on patients' perception of IR function.

RESULTS

Patients undergoing RSA will achieve IR in 3 distinct motion patterns. Analysis of self-reported IR indicated statistically significant difference between the 3 functional types of IR (P < .001). Patient-perceived IR was not significantly different between the 3 studied IR functional types (P = .076) in the analysis of preoperative measures but was significantly different in the postoperative setting (P < .001).

CONCLUSION

Patients attempt IR in 3 distinct functional motion patterns. The improvement of IR after RSA is measured better by patient questionnaires than by physical examination.

Biomechanical effectiveness of tendon transfers to restore active internal rotation in shoulder with deficient subscapularis with and without reverse shoulder arthroplasty

BACKGROUND

Loss of active shoulder internal rotation can be very disabling. Several tendon transfers have been described for the management of an irreparable subscapularis (SSC) tear. The purpose of this study was to determine and compare the internal rotation moment arm (IRMA) of the sternal head of the pectoralis major (PM), latissimus dorsi (LD), and teres major (TM) when transferred to different insertion sites to restore shoulder internal rotation with and without reverse shoulder arthroplasty (RSA).

METHODS

Six fresh-frozen right hemithoraces were prepared and evaluated using a custom tendon transfer model to determine the IRMA of different tendon transfers using the tendon and joint displacement method. Five tendon-transfer pairs were modeled using a single suture and tested before and after implantation of an RSA (Comprehensive; Zimmer-Biomet, Warsaw, IN, USA): PM to the insertion site of the SSC, LD to the anterior insertion site of the supraspinatus (SSP) tendon on the greater tuberosity, LD to SSC, TM to SSP, and TM to SSC. The SSC was not repaired at the end of the RSA procedure to simulate an SSC deficiency. The PM transfer was passed under the conjoined tendon when tested on the intact shoulder and above the conjoined tendon when tested with an RSA.

RESULTS

Tendon transfers were shown to have a significant effect on IRMA. The effect of transferred tendons was significantly affected by the position of the humerus. With the humerus adducted, the IRMA of the TM-SSP (14.1 mm ± 3.1 mm) was significantly greater than the other transfers. With the humerus abducted to 90°, the IRMAs of the LD-SSP (30.0 mm ± 5.4 mm) and TM-SSP (28.4 mm ± 6.6 mm) were significantly greater than the IRMAs of other transfer options. The IRMA of the native shoulder differed significantly from that of the RSA state for all tendon transfers. With the humerus adducted to the side of the body, the IRMA of the RSA PM-SSC transfer was significantly greater than that without an RSA (19.0 mm ± 6.4 mm vs. 7.1 mm ± 0.9 mm), demonstrating increased efficiency for internal rotation in the RSA state.

CONCLUSION

Tendon transfers to restore shoulder internal rotation differ in effectiveness and may be affected by arm position and by implantation of a lateralized humerus/lateralized glenoid RSA. The LD potentially results in superior restoration of shoulder internal rotation in a native shoulder (given the risk of nerve compression with the TM transfer) compared with PM and should be considered as a potential tendon transfer to restore internal rotation in selected patients. In combination with a lateralized humerus/lateralized glenoid RSA, the fulcrum provided by the biomechanics of the semiconstrained implant allows the PM transfer to become a more efficient tendon transfer to restore active internal rotation.

Factors influencing functional internal rotation after reverse total shoulder arthroplasty

Background

Functional internal rotation (fIR) of the shoulder is frequently limited after reverse shoulder arthroplasty (RTSA). The objective of this study was to study a cohort of satisfied patients after RTSA who had comparable active mobility except for fIR and to identify factors associated with selective loss of fIR.

Methods

A retrospective cohort study was conducted to compare 2 patient groups with either poor (≤ 2 points in the Constant-Murley score [CS]) or excellent (≥8 points in CS) fIR after RTSA at a minimum follow-up of 2 years. Influencing factors (demographic, surgical or implant related, radiographic parameters) and clinical outcome were analyzed.

Results

Fifty-two patients with a mean age of 72.8 (±9.3) and a mean follow-up of 41 months were included in the IR≤2 group and 63 patients with a mean age of 72.1 (±8.0) and a mean follow-up of 59 months in the IR≥8 group. All patients had undergone RTSA with the same implant type and only 2 different glenosphere sizes (36 and 40) for comparable indications. A multivariate analysis identified the following significant risk factors for poor postoperative fIR: poor preoperative fIR (pts in CS: 3 [range: 2-6] vs. 6 [range: 4-8], P<.0001), smoking (17.3% vs. 6.5%, P = .004), male gender (59.6% vs. 31.7%, P = .002), less preoperative to postoperative distalization of the greater tuberosity (Δ 19.4 mm vs. 22.2 mm, P = .026), a thin humeral insert (≤3 mm: 23.1% vs. 54.8%, P = .039), and a high American Society of Anesthesiologists score (≤ III: 30.8% vs. 14.3%, P = .043). Subscapularis repair status and glenosphere size had no influence on fIR. Clinical outcome scores improved in both groups from preoperatively to last follow-up. The IR≥8 group had overall significantly better outcome scores compared to the IR≤2 group (Δ 9.3% SSV and Δ 9.5% relative CS, P < .0001). There was no difference in CS between the cohorts when the score for fIR was discarded.

Conclusion

Independent risk factors for poor postoperative fIR after RTSA are poor preoperative fIR, smoking, male gender, less preoperative to postoperative distalization of the greater tuberosity, a thin humeral insert height, and a high American Society of Anesthesiologists score. Except for male gender, these factors are modifiable. These findings may be a valuable addition to patient counselling as well as preoperative planning and preoperative and intraoperative decision-making. The relevance of fIR for overall satisfaction is substantiated by this study.

The influence of posture and scapulothoracic orientation on the choice of humeral component retrotorsion in reverse total shoulder arthroplasty

BACKGROUND

The literature suggests implantation of the humeral component in reverse total shoulder arthroplasty (RTSA) in 0°-40° of retrotorsion without further specification. We hypothesized that optimal humeral component retrotorsion to avoid notching and gain balanced rotational capacity would depend on scapular position and posture.

METHODS

We investigated 200 shoulders in 100 patients with available whole-body computed tomography scans and created 3-dimensional models. Implantation of a humeral component in 20° of retrotorsion was simulated, and a correction angle (CA) to yield perfect opposition to the glenosphere was calculated. Patient-specific variables such as age, sex, posture, and scapular orientation parameters were correlated with this CA.

RESULTS

Scapular orientation showed large interindividual differences. A highly significant correlation was seen between the CA and scapular internal rotation (R = 0.71, P < .001) and protraction (R = 0.39, P < .001). When the CA was adjusted for glenoid retroversion, the correlation coefficient of scapular internal rotation increased even further (R = 0.91, P < .001). Scapular internal rotation itself showed a correlation with thoracic kyphosis (R = 0.27, P < .001), protraction (R = 0.57, P < .001), tilt (R = 0.29, P < .001), and scapular translation (R = -0.23, P < .001).

CONCLUSION

Scapular orientation and posture should be integrated into the determination process of humeral component retrotorsion in RTSA. In theory, implantation of the humeral component with increased retrotorsion leads to improved neutral opposition of the RTSA components in patients with extensive internal rotation of the scapula. On the basis of varying scapular internal rotation, we propose the distinction of 3 different posture types (A-C) for enhanced appraisal of scapulothoracic orientation.

Clinical comparison of humeral-lateralization reverse total shoulder arthroplasty between patients with irreparable rotator cuff tear and patients with cuff tear arthropathy

Background

This study aimed to compare the clinical and radiologic outcomes between patients with irreparable cuff tears (ICTs) and those with cuff tear arthropathy (CTA) after reverse total shoulder arthroplasty (RTSA) with a humeral-lateralization prosthesis.

Methods

A total of 127 patients with ICTs and CTA who underwent RTSA were enrolled and matched at a 1:2 ratio by propensity score. Preoperative shoulder function was assessed for all patients. Radiologic parameters including the acromion-deltoid tuberosity (ADT) distance, lateral humeral offset, and scapular notching were evaluated.

Results

Thirty-four patients in the ICT group and 68 patients in the CTA group were matched for comparison. Preoperatively, mean active forward flexion in the ICT group (89.7° ± 29.4°) was significantly better than that in the CTA group (65.5° ± 24.0°, P < .001). In the CTA group, fatty infiltration of the supraspinatus was worse (3.7 ± 0.5) and the ADT distance was shorter (134.0 ± 12.0 mm) compared with the ICT group preoperatively (3.3 ± 0.8 [P = .008] and 140.7 ± 12.5 mm [P = .001], respectively). There was no significant difference in postoperative functional or radiologic outcomes between the 2 groups. However, gains in active forward flexion (37.9° in ICT group vs. 61.5° in CTA group, P < .01) and abduction (42.1° in ICT group vs. 60.6° in CTA group, P < .01) were significantly greater in the CTA group than in the ICT group.

Conclusions

Shoulder function was significantly improved after RTSA regardless of the preoperative diagnosis. Postoperatively, radiologic findings were not significantly different between the 2 groups. Due to the fact that preoperative range of motion and rotator cuff status were better in patients with ICTs, improvements in active forward flexion and abduction were significantly greater in patients with CTA.