Mitigating the Risk of Instability After Reverse Shoulder Arthroplasty: A Critical Analysis Review of Patient and Surgical Factors.

¼ Instability and dislocation after reverse shoulder arthroplasty may occur in up to 31% of patients.¼ Clinical risk factors for instability include younger age, male sex, increased body mass index, preoperative diagnosis of proximal humerus fracture or rotator cuff pathology, history of instability of the native shoulder or after surgery, and a medical history of Parkinson's disease.¼ Patients with rheumatoid arthritis and decreased proximity to the coracoid may also be at greater risk.¼ In patients at a high risk of instability, surgeons should consider a more lateralized prosthesis (particularly in patients with an incompetent rotator cuff), repairing the subscapularis (particularly when using a medialized prosthesis), and upsizing the glenosphere (>40 mm in male and 38-40 mm in female patients).¼ While potentially useful, less evidence exists for the use of a constrained liner (particularly with a lateralized glenosphere and/or in low-demand patients) and rotating the polyethylene liner posteriorly to avoid impingement.

Survivorship and Clinical Outcomes of Reverse Total Shoulder Arthroplasty in Patients with Large Glenoid Defects Using the Stilting Technique and a Baseplate with Central Ingrowth Cage and Peripheral Locking Screws.

BACKGROUND: Stilting is a novel technique used in reverse shoulder arthroplasty (RSA) in patients with significant glenoid bone loss. This technique utilizes peripheral locking screws placed behind an unseated portion of the baseplate, to transmit forces from the baseplate to the cortical surface of the glenoid, without the need for bone grafting. The stilted screw, once locked, provides a fixed angle point of support for an unseated aspect of a baseplate. The primary advantages of this technique are reduced cost compared to a custom implant and reduced operative time compared to bone grafting. METHODS: We conducted a retrospective, non-randomized, comparative cohort study of 41 patients underwent primary Reverse Shoulder Arthroplasty (RSA) using the Stilting Technique with the Exactech Equinoxe Reverse System (Gainesville, FL, USA) at a single, academic center from the years 2004-2021. Exclusion criteria included age under 18 or over 100, and oncologic or acute fracture RSA indications. Operative data was documented, including implant records, percent baseplate seating, and operative duration. Survivorship was compared among primary stilted-RSA (n=41), bone graft-RSA (n=42), and non-stilted/non-bone grafted RSA (n=1,032) within our institutional shoulder arthroplasty database. A radiographic examination of baseplate failure was also conducted across the study groups. Postoperative functional outcomes were compared in a matched analysis involving patients with a minimum 2-year follow-up between stilted patients and a non-stilted/non-bone grafted control group for primary RSA. RESULTS: All Stilted-RSA cases utilized metal augments and demonstrated a mean baseplate seating of 61% (range 45-75%). For stilted RSAs, survivorship was 100% and 92.6% at 2- and 5-years, compared to 98.3% and 94.6% for non-stilted/non-bone grafted and 96.3% and 79.5% for bone-grafted RSAs (p=0.042). At 5-years, the baseplate-related failure rates were greater in the stilted (7.4%) and the bone-grafted (9.3%) cohorts compared with the non-stilted/non-bone grafted cohort (1.1%, p<0.001). The mean time to baseplate failure was 30 months for stilted RSA. Functional outcomes for primary RSA were statistically similar between stilted and non-stilted patients, including range of motion, Constant, ASES, SST, UCLA, and SPADI scores. CONCLUSION: The stilted-RSA cohort exhibited noninferior revision and baseplate failure rates to that of bone-grafted RSA. This suggests that stilting may be a viable technique for patients undergoing primary RSA with significant glenoid deformity.

Greater distance from the glenosphere center to the acromion reduces risk of acromial impingement in semi-inlay reverse shoulder arthroplasty.

Background: Recently, the issue of subacromial notching, caused by acromial impingement has been reported. The purpose of this study was to assess the impact of differences in the distance between the glenosphere center and the greater tuberosity (DGT) and the distance between the glenosphere center and the acromion (DA) on the closest distance between the greater tuberosity and the acromion during active abduction in shoulders with reverse total shoulder arthroplasty (RSA). Methods: Eleven shoulders with semiinlay RSA were analyzed. Subjects underwent fluoroscopy during active scapular plane abduction. Computed tomography of their shoulders was performed to create three-dimensional (3D) implant models at a mean of 16 months after surgery. Using model-image registration techniques, poses of 3D implant models were iteratively adjusted to match their silhouettes with the silhouettes in the fluoroscopic images (shape matching), and 3D kinematics of implants were computed. The closest distance between the acromion and greater tuberosity was computed at maximum abduction. DA and DGT were measured from 3D surface models. Shoulders were divided into two groups based on DA and DGT measurements and their closest distance data were compared between the groups. Results: There were 7 shoulders with DA ≥ DGT, and 4 shoulders with DA < DGT. Shoulders with DA ≥ DGT showed a significantly wider distance between the greater tuberosity and acromion at maximum abduction compared to those with DA < DGT (5.9 ± 2.4 mm vs. 0.6 ± 0.7 mm, respectively, P = .0021). There were no significant differences in maximum glenohumeral abduction angle and humeral abduction angle between the two groups. Although DA was significantly greater in shoulders with DA ≥ DGT than in those with DA < DGT (43.7 ± 4.4 mm vs. 35.1 ± 6.7 mm, respectively, P = .0275), there was no significant difference in DGT between the two groups. Conclusion: When DGT is less than DA in shoulders with RSA, the closest distance between the greater tuberosity and the acromion at maximum abduction is significantly wider compared to cases where DGT is greater than DA by 3D measurement. Therefore, acromial impingement is less likely to occur in shoulders with RSA when DA is greater than DGT. To avoid acromial impingement, it might be important to make DA greater than DGT.

Rehabilitation protocols in proximal humerus fracture management: A systematic review.

Background: Proximal humerus fractures (PHFs) are relatively common, although optimal rehabilitation is unknown. This review aims to characterize the published rehabilitation regimens utilized for PHFs. Methods: A systematic review was performed per PRISMA guidelines, utilizing PubMed/MEDLINE, Embase, and Cochrane. All studies reporting PHF rehabilitation protocols after nonoperative management, open reduction internal fixation with a plate, or intramedullary nailing were included. Results: Forty articles comprising 3507 patients (66% female, weighted mean age 63.5 years) were included. Substantial variability was present regardless of management. Rehabilitation modalities reported were: sling use in 34 cohorts, most commonly for three weeks; pendulum exercises in 21 cohorts, most commonly starting at post-intervention day 1; post-intervention passive range of motion (ROM) for 30 cohorts, most commonly starting at two days; active-ROM in eight cohorts, most commonly starting at three weeks; active-assisted ROM for 21 cohorts, most commonly starting at three weeks; unlimited ROM for 20 cohorts, most commonly at 4 or 6 weeks; non-weight-bearing for six cohorts, most commonly for six weeks; strengthening for 16 cohorts, most commonly at six weeks; removal of all restrictions for nine cohorts, most commonly starting at six weeks. Conclusions: Published rehabilitation protocols for PHFs vary considerably regardless of management. Future studies comparing methods of management need to consider the influence of postoperative rehabilitation protocol heterogeneity when aggregating data from multiple sites. Level of Evidence: IV.

Reverse Allograft Prosthetic-Composite Versus Endoprosthesis Reconstruction for Massive Proximal Humerus Bone Loss: A Systematic Review and Meta-analysis of Outcomes and Complications.

Background: This systematic review and meta-analysis sought to compare the clinical outcomes after proximal humerus reconstruction with a reverse allograft-prosthetic composite (APC) versus reverse endoprosthesis. Methods: Per PRISMA guidelines, we queried PubMed/MEDLINE, Embase, Web of Science, and Cochrane databases to identify articles reporting clinical outcomes of reverse APC or reverse endoprosthesis reconstruction of the proximal humerus for massive bone loss secondary to tumor, fracture, or failed arthroplasty. We compared postoperative range of motion, outcome scores, and the incidence of complications and revision surgery. Results: Of 259 unique articles, 18 articles were included (267 APC, 260 endoprosthesis). There were no significant differences between the APC and endoprosthesis cohort for postoperative forward elevation (P = .231), external rotation (P = .634), ASES score (P = .420), Constant score (P = .414), MSTS (P = .815), SST (P = .367), or VAS (P = .714). Rate of complications was 15% (31/213) in the APC cohort and 19% (27/144) in the endoprosthesis cohort. The rate of revision surgery was 12% after APC cohort and 7% after endoprosthesis. APC-specific complications included a 10% APC nonunion/malunion/resorption rate and 6% APC fracture/fragmentation rate. Discussion: Reverse APC and endoprosthesis are reasonable options for proximal humerus reconstruction. APC carries additional risks for complications, warranting evaluation of patients' healing capacity and surgeon experience. Level of Evidence: Level IV; Systematic Review. Supplementary Information: The online version contains supplementary material available at 10.1007/s43465-024-01248-7.

The Effect of Socioeconomic Status on Clinical Outcomes and Implant Survivorship After Primary Anatomic and Reverse Total Shoulder Arthroplasty.

BACKGROUND: Low socioeconomic status has been shown to contribute to poor outcomes in patients undergoing joint replacement surgery. However, there is a paucity of studies investigating shoulder arthroplasty. The purpose of this study was to evaluate the effect of socioeconomic status on baseline and postoperative outcome scores and implant survivorship after anatomic and reverse primary total shoulder arthroplasty (TSA). METHODS: A retrospective review of a prospectively-collected single-institution database was performed to identify patients who underwent primary TSA. Zip codes were collected and converted to Area Deprivation Index (ADI) scores. We performed a correlation analysis between national ADI scores and preoperative, postoperative, and pre- to postoperative improvement in range of motion, shoulder strength, and functional outcome scores in patients with minimum 2-year follow-up. Patients were additionally grouped into groups according to their national ADI. Achievement of the MCID, SCB, and PASS and revision-free survivorship were compared between groups. RESULTS: A total of 1,148 procedures including 415 anatomic and 733 reverse total shoulder arthroplasties with a mean age of 64 ± 8.2 and 69.9 ± 8.0 years, respectively, were included. The mean follow-up was 6.3 ± 3.6 years for anatomic and 4.9 ± 2.7 years for reverse TSA. We identified a weak negative correlation between national ADI and most functional outcome scores and range of motion preoperatively (R range 0.07 to 0.16), postoperatively (R range 0.09 to 0.14), and pre- to postoperative improvement (R range 0.01 to 0.17). Thus, greater area deprivation was weakly associated with poorer function preoperatively, poorer final outcomes and poorer improvement in outcomes. There was no difference in the proportion of each ADI group achieving MCID, SCB, and PASS in the anatomic TSA cohort. However, in the reverse TSA cohort, the proportion of patients achieving MCID, SCB, and PASS decreased with greater deprivation. There was no difference in survivorship between ADI groups . CONCLUSIONS: We found a negative effect of low socioeconomic status on baseline and postoperative patient outcomes and range-of-motion; however, the correlations were relatively weak. Patients that reside in socioeconomically deprived areas have poorer functional outcomes before and after TSA and achieve less improvement from surgery. We should strive to identify modifiable factors to improve the success of TSA in socioeconomically deprived areas.

The Effect of Smoking on Outcomes of Reverse Total Shoulder Arthroplasty.

BACKGROUND: The effect of smoking status on clinical outcomes in reverse total shoulder arthroplasty (rTSA) has not been thoroughly characterized. We sought to compare pain and functional outcomes, complications, and revision-free survivorship between current smokers, former smokers, and non-smokers undergoing primary rTSA. METHODS: We retrospectively reviewed a prospectively-collected shoulder arthroplasty database from 2004-2020 to identify patients who underwent primary rTSA. Three cohorts were created based on smoking status: current smokers, former smokers, and non-smokers. Outcome scores (SPADI, SST, ASES, UCLA, Constant), range of motion (ROM) (external rotation [ER], forward elevation [FE], abduction, internal rotation [IR]) and shoulder strength (ER, FE) evaluated at 2-4-year follow-up were compared between cohorts. The incidence of complication and revision-free implant survivorship were evaluated. RESULTS: We included 676 primary rTSAs, including 38 current smokers (44±47 pack-years), 84 former smokers who quit on average 20±14 years (range: 0.5-57 years) prior to surgery (38±32 pack-years), and 544 non-smokers. At 2-4-year follow-up, current smokers had less favorable SPADI, SST, ASES scores, UCLA scores, and Constant scores compared to former smokers and non-smokers. On multivariable analysis, current smokers had less favorable SPADI, SST, ASES score, UCLA score, and Constant score compared to non-smokers. There were no significant differences between cohorts in complication rate and revision-free survivorship. CONCLUSION: Our data showed that current smokers may have poorer functional outcomes after rTSA compared to former smokers and non-smokers despite the incidence of complications and revision surgery not differing significantly between cohorts.

A multi-modal evaluation of experimental pain and psychological function in women with carpometacarpal osteoarthritis.

Objective: Thumb carpometacarpal osteoarthritis (CMC1 OA) is a prevalent and debilitating condition that lacks effective treatments. Understanding the multidimensional pain experience across CMC1 OA disease stages is crucial to improving treatment outcomes. This study examined how radiographic CMC1 OA severity is associated with physical, psychological, and somatosensory function. Method: Thirty-one women with early-stage (Eaton-Littler 1-2) or end-stage (Eaton-Littler 3-4) radiographic CMC1 OA completed validated questionnaires to assess pain, disability, and psychological function. Additionally, experimental pain was measured in each participant using quantitative sensory testing (QST) (mechanical, pressure, vibratory, thermal) at seven body sites (thenar, hypothenar, brachioradialis bi-laterally; quadriceps on affected side). Cohort differences (early-vs. end-stage) across all variables were analyzed using a multivariable modeling approach that included fixed effects and interactions; notably, age was controlled as a confounder. Results: End-stage CMC1 OA participants had higher scores in the pain (p â€‹= â€‹0.01) and function (p â€‹= â€‹0.02) portions of the AUSCAN assessment, self-reported disability of the DASH questionnaire (p â€‹= â€‹0.04), and painDETECT scores (p â€‹= â€‹0.03), indicating greater pain and disability compared to early-stage participants. Additionally, end-stage CMC1 OA participants demonstrated reduced vibratory detection and heat pain thresholds at multiple body sites (p's â€‹< â€‹0.05), with significant interactions observed across the mechanical and cold stimuli. Conclusion: Findings revealed women with end-stage CMC1 OA exhibited increased neuropathic pain characteristics and somatosensory loss compared to those with early-stage CMC1 OA. These results underscore the importance of addressing both peripheral and centralized pain mechanisms and the need for multimodal approaches in the treatment of CMC1 OA.

The effect of tuberosity healing on functional outcomes after reverse shoulder arthroplasty for proximal humerus fractures: a systematic review and meta-analysis.

PURPOSE: This systematic review and meta-analysis compared clinical outcome measures in patients undergoing reverse shoulder arthroplasty (RSA) for proximal humerus fracture (PHF) with healed versus non-healed greater tuberosity (GT). METHODS: We performed a systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines querying PubMed/MEDLINE, EMBASE, Web of Science, and Cochrane for studies that stratified results by the GT healing status. Studies that did not attempt to repair the GT were excluded. We extracted and compared clinical outcomes including postoperative forward flexion (FF), external rotation (ER), internal rotation (IR), Constant score, and complications and revision rates. RESULTS: Of the included patients, 295 (78.5%) demonstrated GT healing while 81 did not (21.5%). The healed GT cohort exhibited increased postoperative FF (P < .001), ER (P < .001), IR (P = .006), and Constant score (P = .006) compared to the non-healed GT cohort. The overall dislocation rate was 0.8% with no study differentiating GT status of dislocation cases. CONCLUSION: Healing of the GT after RSA for PHF yields improved postoperative range of motion and strength, whereas patient-reported pain and function were largely not affected by GT healing indicating merit to RSA for PHF regardless of the likelihood of the GT healing.

Does preoperative forward elevation weakness affect clinical outcomes in anatomic or reverse total shoulder arthroplasty patients with glenohumeral osteoarthritis and intact rotator cuff?

BACKGROUND: This study sought to determine if preoperative forward elevation (FE) weakness affects outcomes of anatomic (aTSA) and reverse total shoulder arthroplasty (rTSA) for patients with rotator cuff-intact glenohumeral osteoarthritis (RCI-GHOA). METHODS: A retrospective review of a single institution's prospectively collected shoulder arthroplasty database was performed between 2007 and 2020, including 333 aTSAs and 155 rTSAs for primary RCI-GHOA with a minimum 2-year follow-up. Defining preoperative weakness as FE strength ≤4.9 lb (2.2 kg), three cohorts were matched 1:1:1 by age, sex, and follow-up: weak (n=82) to normal aTSAs, weak (n=44) to normal rTSAs, and weak aTSAs (n=61) to weak rTSAs. Compared outcomes included range of motion, outcome scores, and complication and revision rates at latest follow-up. RESULTS: Weak aTSAs and weak rTSAs achieved similar postoperative outcome measures to normal aTSAs and normal rTSAs, respectively (P>0.05). Compared to weak rTSAs, weak aTSAs achieved superior postoperative passive (P=0.006) and active external rotation (ER) (P=0.014) but less favorable postoperative Shoulder Pain and Disability Index (P=0.032), American Shoulder and Elbow Surgeons (P=0.024), and University of California, Los Angeles scores (P=0.008). Weak aTSAs achieved the minimal clinically important difference and substantial clinical benefit at a lower rate for abduction (P=0.045 and P=0.003) and FE (P=0.011 and P=0.001). Weak aTSAs had a higher revision rate (P=0.025) but a similar complication rate (P=0.291) compared to weak rTSAs. CONCLUSIONS: Patients with RCI-GHOA and preoperative FE weakness obtain postoperative outcomes similar to patients with normal preoperative strength after either aTSA or rTSA. Preoperatively, weak aTSAs achieved greater ER but lower rates of clinically relevant improvement in overhead motion compared to weak rTSAs. Level of evidence: III.

Outcomes following Humeral Head Autograft Glenoid Reconstruction in Primary Reverse Total Shoulder Arthroplasty.

BACKGROUND: Patients with severe glenoid bone loss are at increased risk for poor implant fixation, scapular notching, dislocation, joint kinematic disturbances, and prosthetic failure following reverse total shoulder arthroplasty (rTSA). Glenoid bone grafting has proven useful when performing rTSA in patients with inadequate glenoid bone stock, although the current literature is limited. The purpose of this study is to evaluate clinical outcomes in patients with significant glenoid deformity undergoing primary rTSA with one-stage glenoid reconstruction using a humeral head autograft. METHODS: A database of prospectively enrolled patients was reviewed to identify patients who underwent primary rTSA with humeral head autograft (n=40) between 2008 and 2020 by six high-volume shoulder arthroplasty surgeons with minimum two-year follow-up. Variables studied included demographics, medical comorbidities, range of motion (ROM), Constant score, American Shoulder and Elbow Surgeons (ASES) score, pain score, patient satisfaction, glenoid deformity, revisions and complications. Preoperative glenoid deformity was characterized using glenoid version and beta-angles, measured on computed tomography (CT). Improvement at final follow-up was compared to a matched control group of 120 standard primary rTSA patients. Following the post hoc Bonferroni correction, an adjusted alpha value of 0.004 was used to define statistical significance. RESULTS: Forty patients were included with a mean follow-up of 5.3 (range, 2.0-13.2) years. Patients exhibited a mean preoperative glenoid retroversion and beta-angle of 29° and 80°, respectively. At final follow-up, patients who received a graft exhibited lower mean scores for active external rotation (25° vs. 39°; p = 0.001) in comparison to those who did not receive a graft. No differences were observed in active abduction (p = 0.029), active forward elevation (p = 0.009), active internal rotation (p = 0.147), passive external rotation (p = 0.082), Global Shoulder Function score (p = 0.157), Constant score (p = 0.036), ASES score (p = 0.009), or pain score (p = 0.186) between groups. Seven patients (17.5%) exhibited complications of which the most common being aseptic glenoid loosening (15%). CONCLUSION: This study demonstrates that patients undergoing primary rTSA with autogenous humeral head autograft for severe glenoid deficiency experience postoperative improvements in ROM and functional outcome scores that exceeded the minimal clinically important difference and substantial clinical benefit but inferior to matched controls. This suggests that glenoid reconstruction using a resected humeral head autograft is an effective strategy when conducting primary rTSA in patients with significant glenoid deformity.

Thresholds for diminishing returns in postoperative range of motion after total shoulder arthroplasty.

BACKGROUND: Satisfaction following total shoulder arthroplasty (TSA), which is commonly reported using patient-reported outcome measures (PROMs), is partially dependent upon restoring shoulder range of motion (ROM). We hypothesized there exists a minimum amount of ROM necessary to perform functional tasks queried in PROM questionnaires, beyond which further ROM may provide no further improvement in PROMs. METHODS: A retrospective review of a multicenter international shoulder arthroplasty database was performed between 2004 and 2020 for patients undergoing anatomic or reverse TSA (aTSA, rTSA), with minimum 2-year follow-up. Our primary outcome was to determine the threshold in postoperative active ROM (abduction, forward elevation [FE], external rotation [ER], and internal rotation [IR] score), whereby additional improvement was not associated with additional improvement in PROMs (Simple Shoulder Test, American Shoulder and Elbow Surgeons score, and the Shoulder Pain and Disability Index). For comparison, we also evaluated the Shoulder Arthroplasty Smart (SAS) score, which is not subject to the ceiling effect. RESULTS: We included 4459 TSAs (1802 aTSAs, 2657 rTSAs) with minimum 2-year follow-up (mean, 56 ± 32 months). The threshold in postoperative ROM that were associated with no further improvement were active abduction, 107-113° for PROMs vs. 163° for the SAS score; active FE, 149-162° for PROMs vs. 176° for the SAS score; active ER, 50-52° for PROMs vs. 72° for the SAS score; IR score, 4-5 points for all PROMs vs. 6 points for the SAS score. Out of 3508 TSAs with complete postoperative ROM data, 8.5% achieved or exceeded all ROM thresholds (14.5% aTSAs, 4.8% rTSAs). CONCLUSIONS: Our findings demonstrate that postoperative ROM exceeding 113° of abduction, 162° of FE, 52° of ER, and IR to L1 is associated with minimal additional improvement in PROMs. While individual patient needs vary, the thresholds may provide helpful targets for patients undergoing postoperative rehabilitation.

Anatomic Versus Reverse Total Shoulder Arthroplasty for Primary Osteoarthritis With an Intact Rotator Cuff: A Midterm Comparison of Early Top Performers.

BACKGROUND: Several surgeons state that their best anatomic total shoulder arthroplasty (aTSA) outperforms their best reverse total shoulder arthroplasty (rTSA) when performed for rotator cuff-intact glenohumeral osteoarthritis. We identified the top-performing aTSAs and rTSAs at short-term follow-up and compared their clinical performance at midterm follow-up to validate this common claim. METHODS: A retrospective review of a multicenter shoulder arthroplasty database was conducted. All shoulders undergoing primary aTSA or rTSA for rotator cuff-intact glenohumeral osteoarthritis between 2007 and 2020 were reviewed. Shoulders with a follow-up clinical visit between 2 and 3 years and a clinical follow-up of minimum 5 years were included. Two separate cohorts were identified: patients with a top 20% (1) American Shoulder and Elbow Surgeons (ASES) score and (2) Shoulder Arthroplasty Smart (SAS) score at 2 to 3 years of follow-up. Clinical outcomes including range of motion, outcome scores, and rates of complications and revision surgeries were compared at minimum 5-year follow-up. RESULTS: The ASES score cohort comprised 185 aTSAs (mean age 67 years, 42% female) and 49 rTSAs (mean age 72 years, 45% female). The SAS score cohort comprised 145 aTSAs (mean age 67 years, 59% female) and 42 rTSAs (mean age 71 years, 57% female). Active external rotation (ER) was greater after aTSA at midterm follow-up in both ASES and SAS score cohorts; however, preoperative to postoperative improvement was equivalent. Postoperative ER and SAS scores were greater after aTSA in both cohorts (P < 0.05); however, no other significant differences in any preoperative or postoperative clinical outcomes were present (P > 0.05), and patients achieved the minimal clinically important difference and substantial clinical benefit at similar rates for all outcomes. No difference was found in the incidence of complications and revision surgeries between top-performing aTSAs and rTSAs. CONCLUSION: Among top-performing shoulder arthroplasties at early follow-up, aTSA does not appear to outperform rTSA, except superior ER at midterm follow-up. LEVEL OF EVIDENCE: Retrospective comparative cohort study, Level Ⅲ.

Establishing the diagnosis of radial tunnel syndrome: a systematic review of published clinical series.

PURPOSE: Radial tunnel syndrome (RTS) is a controversial diagnosis due to non-specific exam findings and frequent absence of positive electromyography (EMG) and nerve conduction study (NCS) findings. The purpose of this study was to identify the methods used to diagnose RTS in the literature. METHODS: We queried PubMed, Embase, Web of Science, and Cochrane databases per PRISMA guidelines. Extracted data included article and patient characteristics, diagnostic assessments utilized and their respective findings, and treatments. Objective data were summarized descriptively. The relationship between reported diagnostic findings (i.e., physical exam and diagnostic tests) and treatments was assessed via a descriptive synthesis. RESULTS: Our review included 13 studies and 391 upper extremities. All studies utilized physical exam in diagnosing RTS; most commonly, patients had tenderness over the radial tunnel (381/391, 97%). Preoperative EMG/NCS was reported by 11/13 studies, with abnormal findings in 8.9% (29/327) of upper extremities. Steroid and/or lidocaine injection for presumed lateral epicondylitis was reported by 9/13 studies (46/295 upper extremities, 16%), with RTS being diagnosed after patients received little to no relief. It was also common to inject the radial tunnel to make the diagnosis (218/295, 74%). The most common reported intraoperative finding was narrowing of the PIN (38/137, 28%). The intraoperative compressive site most commonly reported was the arcade of Frohse (142/306, 46%). CONCLUSIONS: There is substantial heterogeneity in modalities used to diagnose RTS and the reported definition of RTS. This, in conjunction with many patients having concomitant lateral epicondylitis, makes it difficult to compare treatment outcomes for RTS. LEVEL OF EVIDENCE: Level III. Systematic review of retrospective and prospective cohort studies.

Rehabilitation Protocols in Elbow Medial Ulnar Collateral Ligament Injuries: A Systematic Review of Articles Published in the Last 20 Years.

CONTEXT: Elbow medial ulnar collateral ligament (UCL) injuries have become increasingly common in athletes. Despite this, rehabilitation protocols appear to vary drastically, which may explain the clinical equipoise regarding optimal management. OBJECTIVE: This systematic review reports rehabilitation characteristics reported after UCL injuries and compares reported outcomes based on early versus delayed rehabilitation. DATA SOURCES: Our search utilized PubMed/MEDLINE, Embase, Web of Science, and Cochrane to identify all articles on UCL rehabilitation published between January 1, 2002 and October 1, 2022. STUDY SELECTION: Studies in English with ≥5 patients that reported rehabilitation protocols for UCL injuries were evaluated. STUDY DESIGN: Systematic review. LEVEL OF EVIDENCE: Level 4. DATA EXTRACTION: Data included sample characteristics, time to achieve physical therapy milestones, outcome scores, and return-to-play (RTP) rate and timing. RESULTS: Our review included 105 articles with a total of 15,928 elbows (98% male; weighted mean age, 23 years; follow-up, 47 months), with 15,077 treated operatively and 851 treated nonoperatively. The weighted mean time patients spent adhering to nonweightbearing status was 42 days. The mean time until patients were given clearance for active range of motion (ROM) 15 days, full ROM 40 days, and elbow strengthening exercises 32 days. The mean time until all restrictions were lifted was 309 days. The mean time to begin a throwing program was 120 days. Across all rehabilitation characteristics, protocols for patients undergoing nonoperative management started patients on rehabilitation earlier. After UCL reconstruction, earlier active ROM (≤14 days), elbow strengthening (≤30 days), no restrictions (≤180 days), and throwing (≤120 days) postoperatively led to earlier RTP without a negative effect on functional outcome scores. CONCLUSION: Current literature provides a spectrum of protocols for elbow UCL rehabilitation, regardless of management. Nonoperative patients began ROM activities, strengthening, and throwing programs sooner than operative patients, and earlier milestones led to earlier RTP.

Tendon transfers in reverse total shoulder arthroplasty: A systematic review and descriptive synthesis of biomechanical studies.

BACKGROUND: The role of tendon transfer and ideal insertion sites to improve axial rotation in reverse total shoulder arthroplasty (RTSA) is debated. We systematically reviewed the available biomechanical evidence to elucidate the ideal tendon transfer and insertion sites for restoration of external and internal rotation in the setting of RTSA and the influence of implant lateralization. PATIENTS AND METHODS: We queried the PubMed/MEDLINE, Embase, Web of Science, and Cochrane databases to identify biomechanical studies examining the application of tendon transfer to augment shoulder external or internal rotation range of motion in the setting of concomitant RTSA. A descriptive synthesis of six included articles was conducted to elucidate trends in the literature. RESULTS: Biomechanics literature demonstrates that increasing humeral-sided lateralization optimized tendon transfers performed for both ER and IR. The optimal latissimus dorsi (LD) transfer site for ER is posterior to the greater tuberosity (adjacent to the teres minor insertion); however, LD transfer to this site results in greater tendon excursion compared to posterodistal insertion site. In a small series with nearly 7-year mean follow-up, the LD transfer demonstrated longevity with all 10 shoulders having>50% ER strength compared to the contralateral native shoulder and a negative Hornblower's at latest follow-up; however, reduced electromyography activity of the transferred LD compared to the native contralateral side was noted. One study found that transfer of the pectoralis major has the greatest potential to restore IR in the setting of lateralized humerus RTSA. CONCLUSION: To restore ER, LD transfer posterior on the greater tuberosity provides optimal biomechanics with functional longevity. The pectoralis major has the greatest potential to restore IR. Future clinical investigation applying the biomechanical principles summarized herein is needed to substantiate the role of tendon transfer in the modern era of lateralized RTSA. LEVEL OF EVIDENCE: IV; systematic review.

A Systematic Review of Patient Selection Criteria for Outpatient Total Shoulder Arthroplasty.

The utilization of total shoulder arthroplasty (TSA) is increasing, driving associated annual health care costs higher. Opting for outpatient over inpatient TSA may provide a solution by reducing costs. However, there is no single set of accepted patient selection criteria for outpatient TSA. Here, the authors identify and systematically review 14 articles to propose evidence-based criteria that merit postoperative admission. Together, the studies suggest that patients with limited ability to abmluate independently or a history of congestive heart failure may benefit from postoperative at least one night of hospital based monitoring and treatment.

Toxic effects of local anesthetics on rat fibroblasts: An in-vitro study.

BACKGROUND: Infusion catheters facilitate a controlled infusion of local anesthetic (LA) for pain control after surgery. However, their potential effects on healing fibroblasts are unspecified. METHODS: Rat synovial fibroblasts were cultured in 12-well plates. Dilutions were prepared in a solution containing reduced-serum media and 0.9% sodium chloride in 1:1 concentration. Each well was treated with 500 µl of the appropriate LA dilution or normal saline for 15- or 30-min. LA dilutions included: 0.5% ropivacaine HCl, 0.2% ropivacaine HCl, 1% lidocaine HCl and epinephrine 1:100,000, 1% lidocaine HCl, 0.5% bupivacaine HCl and epinephrine 1:200,000, and 0.5% bupivacaine HCl. This was replicated three times. Dilution of each LA whereby 50% of the cells were unviable (Lethal dose 50 [LD50]) was analyzed. RESULTS: LD50 was reached for lidocaine and bupivacaine, but not ropivacaine. Lidocaine 1% with epinephrine is toxic at 30-min at 1/4 and 1/2 sample dilutions. Bupivacaine 0.5% was found to be toxic at 30-min at 1/2 sample dilution. Bupivacaine 0.5% with epinephrine was found to be toxic at 15- and 30-min at 1/4 sample dilution. Lidocaine 1% was found to be toxic at 15- and 30-min at 1/2 sample dilution. Ropivacaine 0.2% and 0.5% remained below LD50 at all time-points and concentrations, with 0.2% demonstrating the least cell death. CONCLUSIONS: Though pain pumps are generally efficacious, LAs may inhibit fibroblasts, including perineural fibroblast and endoneurial fibroblast-like cells, which may contribute to persistent nerve deficits, delayed neurogenic pain, and negatively impact healing. Should a continuous infusion be used, our data supports ropivacaine 0.2%. LEVEL OF EVIDENCE: Basic Science Study; Animal model.

Proximal Row Carpectomy with and without Capitate Resurfacing: A Preliminary Systematic Review and Meta-Analysis.

BACKGROUND: In wrist salvage, proximal row carpectomy (PRC) has increasingly shown superior outcomes to four-corner fusion (4CF). Furthermore, PRC with resurfacing capitate pyrocarbon implants (PRC + RCPIs) provides a treatment option that may allow patients to avoid 4CF or wrist arthrodesis and help restore natural joint function and distribute loads evenly across the implant, though RCPI has yet to be evaluated on a large scale. We aimed to compare outcomes between PRC and PRC + RCPI for the treatment of scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) wrists. METHODS: A systematic review and meta-analysis was performed per Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed/MEDLINE, Embase, Web of Science, and Cochrane were queried for articles on PRC and PRC + RCPI performed for SLAC and SNAC wrist with minimum 12-month follow-up. Primary outcomes included wrist range of motion (ROM), grip strength, and outcome scores including Disabilities of Arm, Shoulder, and Hand (DASH) and QuickDASH scores, Patient-Rated Wrist and Hand Evaluation (PRWHE), and visual analog scale pain scores. RESULTS: Twenty-two studies reporting on 1,804 wrists were included (1,718 PRC alone, 86 PRC + RCPI). PRC + RCPI was associated with greater postoperative radial deviation, but poorer flexion. PRC + RCPI also had significantly lower postoperative QuickDASH (less disability and symptoms) and postoperative PRWHE (lower pain and disability) scores and an improvement in PRWHE compared with PRC. There was no significant difference in grip strength. CONCLUSION: PRC + RCPI demonstrated similar postoperative ROM to PRC alone. While PRC + RCPI was associated with more favorable outcome scores, further research is needed to confirm these findings and assess the incidence and profile of complications related to RCPIs. LEVEL OF EVIDENCE: Level IV. See Instructions for Authors for a complete description of levels of evidence.

Stratification of the minimal clinically important difference, substantial clinical benefit, and patient acceptable symptomatic state after total shoulder arthroplasty by implant type, preoperative diagnosis, and sex.

BACKGROUND: Clinical significance, as opposed to statistical significance, has increasingly been utilized to evaluate outcomes after total shoulder arthroplasty (TSA). The purpose of this study was to identify thresholds of the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) for TSA outcome metrics and determine if these thresholds are influenced by prosthesis type (anatomic or reverse TSA), sex, or preoperative diagnosis. METHODS: A prospectively collected international multicenter database inclusive of 38 surgeons was queried for patients receiving a primary aTSA or rTSA between 2003 and 2021. Prospectively, outcome metrics including ASES, shoulder function score (SFS), SST, UCLA, Constant, VAS Pain, shoulder arthroplasty smart (SAS) score, forward flexion, abduction, external rotation, and internal rotation was recorded preoperatively and at each follow-up. A patient satisfaction question was administered at each follow-up. Anchor-based MCID, SCB, and PASS were calculated as defined previously overall and according to implant type, preoperative diagnosis, and sex. The percentage of patients achieving thresholds was also quantified. RESULTS: A total of 5851 total shoulder arthroplasties (TSAs) including aTSA (n = 2236) and rTSA (n = 3615) were included in the study cohort. The following were identified as MCID thresholds for the overall (aTSA + rTSA irrespective of diagnosis or sex) cohort: VAS Pain (-1.5), SFS (1.2), SST (2.1), Constant (7.2), ASES (13.9), UCLA (8.2), SPADI (-21.5), and SAS (7.3), Abduction (13°), Forward elevation (16°), External rotation (4°), Internal rotation score (0.2). SCB thresholds for the overall cohort were: VAS Pain (-3.3), SFS (2.9), SST 3.8), Constant (18.9), ASES (33.1), UCLA (12.3), SPADI (-44.7), and SAS (18.2), Abduction (30°), Forward elevation (31°), External rotation (12°), Internal rotation score (0.9). PASS thresholds for the overall cohort were: VAS Pain (0.8), SFS (7.3), SST (9.2), Constant (64.2), ASES (79.5), UCLA (29.5), SPADI (24.7), and SAS (72.5), Abduction (104°), Forward elevation (130°), External rotation (30°), Internal rotation score (3.2). MCID, SCB, and PASS thresholds varied depending on preoperative diagnosis and sex. CONCLUSION: MCID, SCB, and PASS thresholds vary depending on implant type, preoperative diagnosis, and sex. A comprehensive understanding of these differences as well as identification of clinically relevant thresholds for legacy and novel metrics is essential to assist surgeons in evaluating their patient's outcomes, interpreting the literature, and counseling their patients preoperatively regarding expectations for improvement. Given that PASS thresholds are fragile and vary greatly depending on cohort variability, caution should be exercised in conflating them across different studies.