Is the subscapularis normal after the open Latarjet procedure? An isokinetic and magnetic resonance imaging evaluation

The moment arms and lines of action of subscapularis after the Latarjet procedure

The Latarjet procedure is an established surgical treatment for recurrent glenohumeral joint instability with glenoid bone loss. Intraoperatively, the conjoint tendon and its attachement on the coracoid bone graft is routed through a split in subscapularis where the graft is fixed to and augments the anteroinferior glenoid. The objective of this in vitro study was to quantify the influence of glenohumeral joint position and conjoint tendon force on the lines of action and moment arms of subscapularis muscle sub-regions after Latarjet surgery. Eight fresh-frozen, entire upper extremities were mounted onto a testing apparatus, and a cable-pulley system was used to apply physiological muscle loading to the major shoulder muscles. The lines of action and moment arms of four subregions of subscapularis (superior, mid-superior, mid-inferior, and inferior) were quantified radiographically with the conjoint tendon unloaded and loaded while the shoulder was in (i) 0° abduction (ii) 90° abduction (iii) 90° abduction and full external rotation (ABER), and (iv) the apprehension position, defined as ABER with 30° horizontal extension. Conjoint tendon loading after Latarjet surgery significantly increased the inferior inclination of the lines of action of the mid-inferior and inferior subregions of subscapularis in the scapular plane in ABER and apprehension positions (p < 0.001), as well as decreased the horizontal flexion moment arm of the inferior subscapularis (p = 0.040). Increased subscapularis inferior inclination may ultimately increase inferior joint shear potential, while smaller horizontal flexion leverage may reduce joint flexion capacity. The findings have implications for Latarjet surgical planning and postoperative rehabilitation prescription.

Faster strength recovery and better strength ratio with arthroscopic Latarjet compared to the open technique: An observational study

INTRODUCTION

The arthroscopic bone block has shown reliability and reproducibility regarding functional scores and shoulder mobility compared to the open bone block technique. The recovery of muscle strength, especially the strength ratio external rotator/internal rotator (ER/IR), is crucial to recovering satisfactory function. This ratio should be as near to 1 as possible, meaning a good strength balance. Little is known about the difference in strength recovery between the open and arthroscopic techniques.

HYPOTHESIS

Arthroscopic Latarjet reduces surgical stress and improves the strength recovery and strength ratio.

OBJECTIVES

To compare arthroscopic and open Latarjet procedures for shoulder muscle strength and functional outcomes.

MATERIAL AND METHODS

It was an observational longitudinal and prospective cohort follow-up. Two groups of patients were accessible for comparison: 35 in an arthroscopy group and 38 in an open group. The main outcome was the muscle strength of shoulder muscles measured with a dynamometer and expressed in Newton (N) at day 21 (D21), D45, D90, D180, and D365 in the operated and contralateral shoulders. The measurements were made for the pectoralis major, the three deltoid fascicles, and the subscapularis. The shoulder ER/IR strength ratio was calculated. Other variables were the range of motion (ROM), the Walch-Duplay (WD), the Western Ontario Shoulder Instability score (WOSI), and the Visual Analogic Scale for pain assessment. The strength, ROM, and functional scores were compared between open and arthroscopy with linear mixed models.

RESULTS

The median strengths at 52 weeks were significantly higher than at 3 weeks (P<10-4): anterior deltoid (AD) 8N (Q1:7, Q3: 9) versus 4N (Q1:2, Q3: 5), lateral deltoid (LD) 9N (Q1:9, Q3: 11) versus 6N (Q1:4, Q3: 7), posterior deltoid (PD) 14N (Q1:12, Q3: 15) versus 9N (Q1:8, Q3: 10), subscapularis 10N (Q1:9, Q3: 12) versus 7N (Q1:5, Q3: 8), and pectoralis major (PM) 11N (Q1:9, Q3: 12) versus 7N (Q1:5, Q3: 10). The overall strengths were lower in the open group compared to the arthroscopy group: AD -2.1N (CI95%[-3.1--1.2], p=0.0005), LD -1.3N (CI95% [-2.4--0.15], p=0.03), PD -0.35N (CI95% [-1-0.9], p=0.52), subscapularis -2.1N (CI95% [-3.3--0.7], p=0.006), and PM -1.4N (CI95% [-2.2--0.02], p=0.03). The ER/IR ratio was stable throughout the follow-up for both the operated and contralateral shoulders (p>0.5). The overall mean ratio was 1.3 (median 1.2, Q1: 1, Q3:1.45) for the operated shoulder and 1.1 (median 1, Q1: 0.9, Q3:1.3) for the contralateral shoulder (p=0.0004). The average ER/IR ratio was 0.27 points higher in the open group (CI95% [0.1-0.46], p=0.003). The ROM was similar between the two groups, and there was no correlation between the ER/IR ratio and the ROM (p>0.5). The VAS < 3 weeks and WD > 12 weeks were significantly poorer in the open group: +0.61 (CI95% [0.03-1.16] p=0.02), and -7.3 points (CI95% [-13--0.01], p=0.05), on average, respectively.

CONCLUSION

The patients in the arthroscopy group had a better ER/IR strength ratio (closer to 1) and better WOSI after 12 weeks. The strength and the ROM were not correlated with each other.

LEVEL OF EVIDENCE

III.

The Subscapularis-Sparing "Flipped Latarjet" Procedure

The Latarjet procedure is a proven and effective operation to treat anterior shoulder instability. Especially in cases with anterior glenoid bone loss, the Latarjet operation is the most popular procedure to restore glenoid anatomy and avoid further dislocations. Next to the re-creation of the missing glenoid bone, the sling effect of the conjoint tendon transferred between a split in the subscapularis muscle is an important "soft tissue stabilizer" of the humeral head. However, it has been shown that the inferior part of the subscapularis muscle tends to degenerate, leading to fatty infiltration of the muscle itself. Also, exposure through the subscapularis split is technically demanding, and there is a risk of nerve damage due to the pulling forces of the retractors during open surgery. When performing the procedure arthroscopically, extremely low and medial portals are necessary to find a correct angle for the glenoid drilling when approaching from anterior. Neurovascular structures may be at risk during these surgical steps. The aim of the flipped Latarjet procedure is to facilitate a safe and reliable arthroscopic operation to anteriorly stabilize the shoulder by transferring the coracoid to the deficient glenoid without splitting the subscapularis muscle while keeping the benefits of a sling effect of the conjoined tendon.

The Arthroscopic Subscapular Sling Procedure Results in Low Recurrent Anterior Shoulder Instability at 24 Months of Follow-Up

PURPOSE

To analyze the results of the subscapular sling procedure developed for anterior shoulder instability in patients with less than 10% anterior glenoid bone loss.

METHODS

Patients were treated surgically with the arthroscopic subscapular sling procedure. A semitendinosus graft was used to reconstruct the anterior labrum and to establish a sling suspension around the upper part of the subscapularis tendon. The patients were followed up with radiographs (at 12 and 24 months). Magnetic resonance imaging (MRI) of the shoulder region and clinical examinations were performed at 3, 12, and 24 months. Recurrent dislocation was the primary endpoint. The Western Ontario Shoulder Instability Index (WOSI) and MRI results were secondary outcome measures. An independent physiotherapist assessed residual instability and range of motion.

RESULTS

Fifteen patients were included with a dislocation rate of 0% after 24 months follow-up. There was a significant clinical improvement of the WOSI score from 57% (904) at baseline to 88% (241) at 24 months (P < .001). The proportion of patients with an improvement in the WOSI Total score larger than the estimated minimal clinically important difference was 100% both at 12 and 24 months. MRI showed an intact sling in all patients. External rotation was not significantly reduced (52° at baseline vs 47° at 24 months, P = .211). Flexion and abduction were significantly improved from 152° to 174° (P = .001) and 141° to 170° (P < .001) after 24 months. The surgical procedures were completed without any intraoperative complications.

CONCLUSIONS

The subscapular sling procedure resulted in low recurrent shoulder instability and improved patient-reported outcome measures at 24 months of follow-up.

LEVEL OF EVIDENCE

Level IV, case series.

Strength after the arthroscopic Latarjet procedure: Are shoulder internal rotation, elbow flexion & supination strength decreased?

Background

The Latarjet procedure is an effective shoulder stabilizing surgery, however, the procedure results in an alteration of anatomy that may result in shoulder and elbow weakness. Thus, the purpose of this study was to assess post-operative shoulder and elbow strength after the Latarjet procedure. We hypothesized that shoulder and elbow strength are not affected after the procedure.

Methods

The study group consisted of patients that had undergone the arthroscopic Latarjet procedure. An isokinetic dynamometer was used to evaluate the strength of bilateral shoulder internal rotation, elbow flexion, forearm supination using peak torque (N/m), as well as grip strength (kilograms). Shoulder range of motion and the potential effects of hand dominance were further analysed.

Results

Nineteen patients with a mean age of 29 years and an average follow up of 47 months were included. Shoulder internal rotation strength, elbow flexion and forearm supination strength and grip strength were not significantly different when compared to the non-operative side (p > 0.13). The range of shoulder external rotation was significantly reduced (p < 0.001) on the Latarjet side.

Conclusion

The results from this study demonstrate no statistically significant differences in the strength of shoulder internal rotation, elbow flexion, forearm supination or grip strength despite the surgical alterations to the subscapularis and conjoint tendon.

[Translated article] Latarjet procedure for shoulder instability: Implications in the innervation of the subscapularis muscle

INTRODUCTION

Our aim was to describe whether Latarjet's technique affects subscapularis muscle innervation.

MATERIALS AND METHODS

We studied 12 embalmed shoulders. Subscapularis muscle innervation pattern was registered. Dimensions of the subscapularis at the glenohumeral joint line and the nerves entry point were measured. Horizontal distances from the nerves to the glenohumeral joint line as well as vertical ones to the split were measured before and after Latarjet procedure. A safe zone for the split was designed to avoid damage to subscapularis innervation.

RESULTS

Subscapularis muscle is innervated by three principal branches: upper, middle, and inferior subscapularis nerves. No statistical differences were found between innervation distances before and after Latarjet procedure. To perform subscapularis split along the muscle safe zone, two thirds' proportions throughout all the split must be maintained.

CONCLUSIONS

Subscapularis muscle has a triple innervation and was not altered after Latarjet procedure. Therefore, Latarjet technique seems to respect subscapularis muscle innervation if its split is placed through the subscapularis muscle safe zone.

Latarjet procedure for shoulder instability: Implications in the innervation of the subscapularis muscle

INTRODUCTION

Our aim was to describe whether Latarjet's technique affects subscapularis muscle innervation.

MATERIALS AND METHODS

We studied 12 embalmed shoulders. Subscapularis muscle innervation pattern was registered. Dimensions of the subscapularis at the glenohumeral joint line and the nerves entry point were measured. Horizontal distances from the nerves to the glenohumeral joint line as well as vertical ones to the split were measured before and after Latarjet procedure. A safe zone for the split was designed to avoid damage to subscapularis innervation.

RESULTS

Subscapularis muscle is innervated by three principal branches: upper, middle, and inferior subscapularis nerves. No statistical differences were found between innervation distances before and after Latarjet procedure. To perform subscapularis split along the muscle safe zone, two thirds' proportions throughout all the split must be maintained.

CONCLUSIONS

Subscapularis muscle has a triple innervation and was not altered after Latarjet procedure. Therefore, Latarjet technique seems to respect subscapularis muscle innervation if its split is placed through the subscapularis muscle safe zone.

Changes in Scapular Function, Shoulder Strength, and Range of Motion Occur After Latarjet Procedure

Purpose

To evaluate the current literature on the effects of anatomic changes caused by the Latarjet procedure and to identify areas for future research.

Methods

English-language studies that addressed the consequences of anatomic alterations after the open Latarjet procedure were included. Articles written in languages other than English, reviews, and case reports were excluded. Titles and abstracts were screened by 2 authors. Studies that met the inclusion criteria were screened by the same authors. The following data were extracted from the included studies: authors, year of publication, journal, country of origin, aims or purpose, study population and sample size, methods, procedure, intervention type, and key findings that relate to the scoping review questions.

Results

Twenty-two studies were included for analysis, yielding the following findings: First, the Latarjet procedure may change the position of the scapula owing to pectoralis minor tenotomy and/or transfer of the conjoint tendon. Second, dissection of the coracoacromial ligament may result in increased superior translation of the humeral head. The impact of this increased translation on patients' function remains unclear. Third, the subscapularis split shows, overall, better internal rotation strength compared with subscapularis tenotomy. Fourth, passive external rotation may be limited after capsular repair. Fifth, despite the movement of the conjoint tendon, elbow function seems unchanged. Finally, the musculocutaneous nerve is lengthened with a changed penetration angle into the coracobrachialis muscle, but the clinical impact seems limited.

Conclusions

The Latarjet procedure leads to anatomic and biomechanical changes in the shoulder. Areas of future research may include better documentation of scapular movement (bilateral, as well as preoperative and postoperative) and elbow function, the effect of (degenerative) rotator cuff ruptures after the Latarjet procedure on shoulder function, and the impact of capsular closure and its contribution to the development of glenohumeral osteoarthritis.

Clinical Relevance

This comprehensive overview of anatomic changes after the Latarjet procedure, with its effects on shoulder and elbow function, showed gaps in the current literature. Orthopaedic shoulder surgeons and physical therapists could use our findings when providing patient information and performing future clinical research.

The arthroscopic treatment of anterior shoulder instability with glenoid bone loss shows similar clinical results after Latarjet procedure and iliac crest autograft transfer

PURPOSE

Recurrent anterior shoulder instability caused by critical bone loss of the glenoid is a challenging condition for shoulder surgeons. The purpose of this prospective multicenter trial was to compare the arthroscopic transfer of the coracoid process (Latarjet procedure) with the arthroscopic reconstruction of the glenoid using iliac crest autografts.

METHODS

A prospective multi-center trial was performed in nine orthopaedic centres in Austria, Germany and Switzerland between July 2015 and August 2021. Patients were prospectively enrolled and received either an arthroscopic Latarjet procedure or an arthroscopic iliac crest graft transfer. Standardized follow-up after 6 months and mimimum 24 months included range of motion, Western Ontario stability index (WOSI), Rowe score and subjective shoulder value (SSV). All complications were recorded.

RESULTS

177 patients (group Latarjet procedure: n = 110, group iliac crest graft: n = 67) were included in the study. WOSI (n.s.), SSV (n.s.) and Rowe score (n.s.) showed no difference at final follow-up. 10 complications were seen in group Latarjet procedure and 5 in group iliac crest graft; the frequency of complications did not differ between the two groups (n.s.).

CONCLUSION

The arthrosopic Latarjet procedure and arthroscopic iliac crest graft transfer lead to comparable results regarding clinical scores, frequency of recurrent dislocations and complication rates.

LEVEL OF EVIDENCE

Level II.

Navigation-Guided Trans-glenoid Flexible Fixation Technique for Arthroscopic Autologous Iliac Crest Grafting Treatment of Recurrent Shoulder Dislocation

Recurrent anterior shoulder dislocations accompanied by severe glenoid bone defects are typically treated with arthroscopy. Until now, autologous iliac grafting has been reported with excellent results, and different techniques of bone fixation have been introduced by numerous scholars. In this article, we introduce a specially designed guide that can achieve accurate positioning of the bone graft and a nonrigid graft fixation technique with a single EndoButton (Smith & Nephew). Using this technique, we greatly simplify the arthroscopic procedure and avoid the use of screws.

Primary Open Latarjet Procedure Results in Functional Differences but No Structural Changes in Subscapularis Muscle Quality vs the Healthy Contralateral Shoulder at Long-term Follow-up

BACKGROUND

There are concerns that the Latarjet procedure results in loss of glenohumeral rotation and strength and in subscapularis dysfunction. The long-term effects of this procedure on subscapularis quality, glenohumeral rotation, and strength are unknown.

PURPOSE/HYPOTHESIS

To analyze the long-term effect of the primary open Latarjet procedure using a muscle-splitting approach on internal and external rotation and strength, as well as subscapularis muscle quality as compared with the healthy contralateral side. We hypothesized that the primary open Latarjet procedure is associated with a reduction of long-term shoulder strength and function and decreased subscapularis quality.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 42 patients who underwent a primary open Latarjet procedure for recurrent anterior shoulder instability at a mean age of 26 years (range, 18-36) were reviewed after a mean follow-up of 8.4 years (range, 5-12). The subscapularis muscle volume and fat fraction of both shoulders were assessed. Bilateral active internal rotation (IR) and external rotation (ER), as well as IR and ER strength, were assessed by isokinetic testing (concentric, eccentric, and fatigability).

RESULTS

Active IR (0.6-point difference, P < .001) and ER (4° difference, P = .010) were significantly greater in healthy contralateral shoulders. The IR strength of the operated shoulder was significantly less than that of the healthy shoulder in concentric and eccentric testing (range of deficit, 4%-6%; P < .05). Also, the ER strength of the operated shoulder was significantly less than that of the healthy shoulder in concentric testing (11% deficit, P < .05). Subscapularis muscle volume was significantly greater in the operated shoulder (4% difference, P = .022), and there was no significant difference in fat fraction (P = .114).

CONCLUSIONS

The primary open Latarjet procedure was associated with significantly decreased active IR and ER and strength when compared with the healthy contralateral shoulder. The clinical influence of these findings is yet to be defined. There was no increased subscapularis muscle fatty degeneration but a minimal hypertrophy on the operated side at long-term follow-up.

Anterior Shoulder Instability Part II-Latarjet, Remplissage, and Glenoid Bone-Grafting-An International Consensus Statement

PURPOSE

The purpose of this study was to establish consensus statements via a modified Delphi process on the Latarjet procedure, remplissage, and glenoid-bone grafting for anterior shoulder instability.

METHODS

A consensus process on the treatment utilizing a modified Delphi technique was conducted, with 65 shoulder surgeons from 14 countries across 5 continents participating. Experts were assigned to one of 9 working groups defined by specific subtopics of interest within anterior shoulder instability.

RESULTS

The technical approaches identified in the statements on the Latarjet procedure and glenoid bone-graft were that a subscapularis split approach should be utilized, and that it is unclear whether a capsular repair is routinely required. Furthermore, despite similar indications, glenoid bone-grafting may be preferred over the Latarjet in patients with bone-loss greater than can be treated with a coracoid graft, and in cases of surgeon preference, failed prior Latarjet or glenoid bone-grafting procedure, and epilepsy. In contrast, the primary indications for a remplissage procedure was either an off-track or engaging Hill-Sachs lesion without severe glenoid bone loss. Additionally, in contrast to the bone-block procedure, complications following remplissage are rare, and loss of shoulder external rotation can be minimized by performing the tenodesis via the safe-zone and not over medializing the fixation.

CONCLUSION

Overall, 89% of statements reached unanimous or strong consensus. The statements that reached unanimous consensus were the prognostic factors that are important to consider in those undergoing a glenoid bone-grafting procedure including age, activity level, Hill-Sachs Lesion, extent of glenoid bone-loss, hyperlaxity, prior surgeries, and arthritic changes. Furthermore, there was unanimous agreement that it is unclear whether a capsular repair is routinely required with a glenoid bone graft, but it may be beneficial in some cases. There was no unanimous agreement on any aspect related to the Latarjet procedure or Remplissage.

LEVEL OF EVIDENCE

Level V, expert opinion.

Structural and Functional Results of Subscapularis and Conjoint Tendon After Latarjet Procedure at 8-Year Average Follow-up

BACKGROUND

The Latarjet procedure involves initial dissection through a longitudinal split of the subscapularis tendon with only a final partial closure to accommodate the transferred coracoid bone. Furthermore, by transferring the coracoid bone block to the anterior glenoid, the surgeon completely alters the resting and dynamic route of the attached conjoint tendon. The eventual structural and functional integrity of the subscapularis and conjoint tendons is currently unknown.

PURPOSE

To examine the structural and functional integrity of the subscapularis and the conjoint tendon after the Latarjet procedure at an 8-year average follow-up.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Twenty patients with anterior shoulder instability at a mean age of 30 years (range, 19-50 years) underwent the open Latarjet procedure. Clinical examination at the final follow-up included quantitative isometric measurement of abduction and internal rotation strength compared with the nonoperative side. Patients were assessed via radiograph examination and preoperative computed tomography. Final position and healing of the transferred coracoid bone block were evaluated using standard radiographs. At follow-up, the subscapularis and conjoint tendon were evaluated via magnetic resonance imaging (MRI) with metal artifact reduction techniques and via ultrasound.

RESULTS

Nineteen of the 20 shoulders remained stable at the final follow-up; there was 1 redislocation (5%) after 14 months. The mean Rowe score was 83 points (SD, 17.9 points), the mean Constant score was 85 points (SD, 8.1 points), and the Subjective Shoulder Value was 80% (SD, 18%). The mean abduction strength of the operative shoulder was 7.41 ± 2.06 kg compared with 8.33 ± 2.53 kg for the nonoperative side (P = .02). The mean internal rotation strength at 0° for the operative shoulder was 8.82 ± 3.47 kg compared with 9.06 ± 3.01 kg for the nonoperative side (P = .36). The mean internal rotation strength in the belly-press position for the operative shoulder was 8.12 ± 2.89 kg compared with 8.50 ± 3.03 kg (P = .13). Four of 20 shoulders showed mild tendinopathic changes of the subscapularis tendon but no partial or complete tear. One patient exhibited fatty degeneration Goutallier stage 1. Conjoint tendon was in continuity in all 20 shoulders on MRI scans.

CONCLUSION

Abduction, but not internal rotation strength, was slightly reduced after the Latarjet procedure at a mean of 8 years of follow-up. The subscapularis tendon was intact based on ultrasound examination, and the conjoint tendon was intact based on MRI scans. Subscapularis muscle girth relative to the supraspinatus muscle remained intact from preoperative measurements based on MRI scans.

Early Complication Rates Following Total Shoulder Arthroplasty for Instability Arthropathy With a Prior Coracoid Transfer Procedure

The purpose of this study was to report early complications for anatomic total shoulder arthroplasty (aTSA) performed for instability arthropathy after a prior coracoid transfer procedure and compare them with those of a control group of patients following aTSA for primary osteoarthritis. A retrospective review was performed of 14 patients after aTSA with a prior coracoid transfer procedure. A control group of 42 patients with an aTSA for primary osteoarthritis were matched 3:1 according to age, sex, body mass index, comorbidities, and dominant shoulder. Chart reviews identified any complications within 1 year, in addition to blood loss and operative time in both groups. Preoperative computed tomography scans were used to determine Walch glenoid classification and Goutallier classification of the subscapularis. The mean operative time was not significantly different between the coracoid transfer cohort and the control group, and the mean estimated blood loss was only 6.9 mL greater in the coracoid transfer group. The coracoid transfer group had 2 (14.3%) patients with complications, with 1 early revision for an acute deep infection. The control group had 4 (9.5%) complications in 3 (7.1%) patients, with no early revisions. There was no statistical difference in complications between the groups (P=.618). Anatomic TSA for instability arthropathy after coracoid transfer had similar operative time, blood loss, and 1-year complication rates as those of the control group. These results provide some evidence to support the continued use of aTSA in select patients with instability arthropathy after prior coracoid transfer procedure. [Orthopedics. 2021;44(4):e482-e486.].

Avaliação isocinética do ombro após procedimento cirúrgico de Bristow/Latarjet em atletas

Objectives  To evaluate the muscular strength of the internal (IR) and external (ER) rotators of the shoulder after Bristow/Latarjet surgery.

Methods  Cross-sectional study with 18 patients (36 shoulders). The isokinetic evaluation was performed using the Biodex 3 System Pro dynamometer (Biodex Medical System, Inc., Shirley, NY, USA). The athletic shoulder outcome rating scale (ASORS) and the visual analogue scale (VAS) were applied.

Results  The values of peak torque and maximum work in concentric and eccentric mode on the non-operated shoulder were higher than on the operated side for both the IR and ER ( p  < 0.01). The conventional and functional balance between the ER and IR showed no differences between the operated and the non-operated side. When comparing patients with postoperative time < 1 year or 1 year, no differences were observed in peak torque values at 60°/s and 240°/s and maximum work at 60°/s and 240°/s of the IR to the operated shoulder. However, the peak torque values of 60°/s and 240°/s and maximum work at 60°/s and 240°/s of the ER were higher in subjects with postoperative time ≥ 1 year in all variables ( p  < 0.05).

Conclusions  There was a decrease in the strength of the IR and ER in the operated shoulder compared with the healthy shoulder. However, the conventional and functional balance was maintained.

Comparison of Structural Subscapularis Integrity After Latarjet Procedure Versus Iliac Crest Bone Graft Transfer

Background:

Although clinical outcome scores are comparable after coracoid transfer procedure (Latarjet) and iliac crest bone graft transfer (ICBGT) for anterior shoulder instability with glenoid bone loss, a significant decrease in internal rotation capacity has been reported for the Latarjet procedure.

Hypothesis:

The subscapularis (SSC) musculotendinous integrity will be less compromised by ICBGT than by the Latarjet procedure.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

We retrospectively analyzed pre- and postoperative computed tomography (CT) scans at short-term follow-up of 52 patients (26 Latarjet, 26 ICBGT) previously assessed in a prospective randomized controlled trial. Measurements included the preoperative glenoid defect area and graft area protruding the glenoid rim at follow-up and tendon thickness assessed through SSC and infraspinatus (ISP) ratios. Fatty muscle infiltration was graded according to Goutallier, quantified with muscle attenuation in Hounsfield units, and additionally calculated as percentages. We measured 3 angles to describe rerouting of the SSC musculotendinous unit around the bone grafts.

Results:

SSC fatty muscle infiltration was 2.0% ± 2.2% in the Latarjet group versus 2.4% ± 2.2% in ICBGT (P = .546) preoperatively and showed significantly higher values in the Latarjet group at follow-up (5.3% ± 4.5% vs 2.3% ± 1.7%; P = .001). In total, 4 patients (15.4%) in the Latarjet group showed a progression from grade 0 to grade 1 at follow-up, whereas no changes in the ICBGT group were noted. The measured rerouting angle of the SSC muscle was significantly increased in the Latarjet group (11.8° ± 2.1°) compared with ICBGT (7.5° ± 1.3°; P < .001) at follow-up, with a significant positive correlation between this angle and fatty muscle infiltration (R = 0.447; P = .008). Ratios of SSC/ISP tendon thickness were 1.03 ± 0.3 in the Latarjet group versus 0.97 ± 0.3 (P = .383) in ICBGT preoperatively and showed significantly lower ratios in the Latarjet group (0.7 ± 0.3 vs 1.0 ± 0.2; P < .001) at follow-up.

Conclusion:

Although clinical outcome scores after anterior shoulder stabilization with a Latarjet procedure and ICBGT are comparable, this study shows that the described decline in internal rotation capacity after Latarjet procedure has a radiographic structural correlate in terms of marked thinning and rerouting of the SSC tendon as well as slight fatty degeneration of the muscle.

Isokinetic evaluation of the shoulder and elbow after Latarjet procedure

BACKGROUND/HYPOTHESIS

The Latarjet procedure changes the anatomy of the shoulder, moving the coracoid process distally through an incision in the subscapularis muscle. Some authors have studied the effect of this surgery on shoulder rotator strength. Our hypothesis is that the Latarjet procedure decreases elbow supination and flexion strength.

METHODS

A retrospective case series, evaluating patients submitted to the Latarjet procedure between May 2013 and June 2017. Movements of the elbow (supination, pronation, flexion and extension) and shoulder (internal and external rotation) were evaluated bilaterally using a Biodex System 3 isokinetic dynamometer (Biodex Medical Systems, New York) in concentric/concentric mode.

RESULTS

We evaluated 20 patients with an average follow-up of 36 months. In the elbow, we observed a 9.1% decrease in supination strength at a speed of 60°/s (p=0.044), without statistical difference at 120°/s (p=0.570). In the shoulder, there was a 13.5% decrease in external rotation strength at 60°/s and 4.5% at 180°/s (p=0.009 and p=0.040, respectively). The other movements did not demonstrate any statistically significant differences.

CONCLUSION

After the Latarjet procedure, the supination strength at 60°/s was decreased, as was the external rotation strength of the shoulder at 60°/s and 180°/s. We did not observe any reduction in strength for shoulder flexion or internal shoulder rotation.

LEVEL OF EVIDENCE

IV, case series.

Outcomes of total shoulder arthroplasty for instability arthropathy with a prior coracoid transfer procedure: a retrospective review and matched cohort

BACKGROUND

Many surgeons are concerned about reports of increased complications, worse outcomes, and early failures in patients undergoing anatomic total shoulder arthroplasty after coracoid transfer. The purpose of this study was to evaluate minimum 2-year outcomes following anatomic total shoulder arthroplasty for instability arthropathy with a prior coracoid transfer procedure and compare them with a matched cohort of patients undergoing total shoulder arthroplasty for primary osteoarthritis.

METHODS

We identified 11 primary anatomic total shoulder arthroplasties performed by a single surgeon for instability arthropathy with a prior coracoid transfer procedure with a minimum of 2 years' follow-up (mean, 58 ± 35 months). A matched cohort of 33 patients with a total shoulder arthroplasty for primary osteoarthritis served as the control group. The American Shoulder and Elbow Surgeons (ASES) score, Single Assessment Numeric Evaluation (SANE) score, patient satisfaction, complications, and revisions were evaluated in both cohorts.

RESULTS

The coracoid transfer cohort showed no difference in the final ASES score (88 vs. 82, P = .166) or SANE score (85 vs. 67, P = .120) vs. the matched cohort. The postoperative ASES pain score (45 vs. 41, P = .004) was higher in the coracoid transfer cohort, but the mean improvement from preoperative to postoperative values for the ASES score (P = .954), ASES pain score (P = .183), and SANE score (P = .293) was no different between cohorts. Both cohorts had high patient satisfaction without a statistically significant difference (P = .784).

CONCLUSION

At early- to mid-term follow-up, total shoulder arthroplasty performed after a coracoid transfer demonstrated similar results to total shoulder arthroplasty performed for primary osteoarthritis. Longer follow-up and larger patient cohorts will provide further insights and highlight any potential differences in outcomes or revision rates.

Subscapularis structural integrity and function after arthroscopic Latarjet procedure at a minimum 2-year follow-up

BACKGROUND

Subscapularis function after arthroscopic Bankart repair has been widely studied. However, data regarding subscapularis performance after arthroscopic Latarjet procedures are lacking. This study aimed to evaluate subscapularis clinical and radiologic performance after arthroscopic Latarjet procedures.

METHODS

We included 40 patients who underwent arthroscopic Latarjet procedure with a minimum 2-year follow-up. Clinical evaluation included Western Ontario Shoulder Instability Index and Rowe scores, specific subscapularis isokinetic study, and lift-off tests. Contralateral measurements were used for comparison. Computed tomographic evaluation included graft consolidation, muscle dimensions, and degree of fatty atrophy, calculated as the mean muscle attenuation (MMA).

RESULTS

There was a decrease of 8.3% of maximum internal rotation peak torque in the operated arm (P = .02). However, there was no significant difference in the agonist-antagonist ratio: 76.9% in the operated arm and 76% in the contralateral (P = .82). Lift-off strength test demonstrated a decrease in the first year but not at final follow-up (P = .38). There was a significant decrease in lift-off distance of 23% compared to the contralateral side (P < .001). Subscapularis MMA was diminished when compared to the infraspinatus/teres minor (P < .001) at the expense of its upper part (P = .03). Hyperlaxity and number of dislocation episodes were correlated to a lower MMA (P = .046 and P = .005).

CONCLUSION

Arthroscopic Latarjet procedures provide satisfactory clinical results. There seems to be a diminished subscapularis MMA depending on its superior half. Hyperlaxity and number of previous dislocations were correlated to a lower MMA. Although there was a decrease in the maximum internal rotation peak torque, we did not find any difference in the agonist-antagonist ratio or in the final lift-off strength between sides.

All-arthroscopic glenoid reconstruction by iliac crest bone graft transfer does not affect structural integrity and 3-dimensional volume of the subscapularis muscle

AIM

The subscapularis muscle is an important active stabilizer of the glenohumeral joint. For this radiological study, we investigated if its radiological integrity is affected after arthroscopic glenoid reconstruction. In the technique used, an autologous iliac crest graft is transported through the rotator interval, and the graft is fixed via an antero-inferior portal with compression screws.

METHODS

3 women and 6 men (mean age 31 ± 9 years, min 21, max 46 years) who had a preoperative glenoid deficit of 23% ± 6% (min 13%, max 29%) were included. In a follow-up after an interval of 34 months (min 19, max 50), MRI scans were performed on both shoulders. With ITK-SNAP, a 3D reconstruction software, the volume of the subscapularis muscle in the injured and contralateral shoulder was measured. In addition, signal intensity ratios (PSI) (infraspinatus muscle / cranial subscapularis muscle and infraspinatus muscle / caudal subscapularis muscle) were analyzed and the width of the cranial and caudal portions as well as the length of the subscapularis muscle in the parasagittal plane were determined.

RESULTS

The 3D volume showed no difference between operated and healthy shoulders (p = 0.07), neither did PSI ratios (infraspinatus muscle / cranial subscapularis muscle: p = 1.00, infraspinatus muscle / caudal subscapularis muscle: p = 1.00). In the parasagittal plane, length (p = 0.09) and cranial width (p = 0.23) did not differ. However, the width of the lower muscle was increased in injured shoulders (p = 0.02).

CONCLUSION

In this cohort, no relevant volume loss could be found after arthroscopic glenoid reconstruction. However, a greater width of the lower muscle portion could be identified in the parasagittal plane as a possible indication of scarring.

Neer Award 2019: Latarjet procedure vs. iliac crest bone graft transfer for treatment of anterior shoulder instability with glenoid bone loss: a prospective randomized trial

BACKGROUND

The Latarjet and iliac crest bone graft transfer (ICBGT) procedures are competing treatment options for anterior shoulder instability with glenoid bone loss.

METHODS

In this bicentric prospective randomized study, 60 patients with anterior shoulder instability and glenoid bone loss were included and randomized to either an open Latarjet or open ICBGT (J-bone graft) procedure. Clinical evaluation was completed before surgery and 6, 12, and 24 months after surgery, including the Western Ontario Shoulder Instability index, Rowe score, Subjective Shoulder Value, pain level, satisfaction level, and work and sports impairment, as well as assessment of instability, range of motion, and strength. Adverse events were prospectively recorded. Radiographic evaluation included preoperative, postoperative, and follow-up computed tomography analysis.

RESULTS

None of the clinical scores showed a significant difference between the 2 groups (P > .05). Strength and range of motion showed no significant differences except for diminished internal rotation capacity in the Latarjet group at every follow-up time point (P < .05). A single postoperative traumatic subluxation event occurred in 2 ICBGT patients and 1 Latarjet patient. The type and severity of other adverse events were heterogeneous. Donor-site sensory disturbances were observed in 27% of the ICBGT patients. Computed tomography scans revealed a larger glenoid augmentation effect of the ICBGTs; this, however, was attenuated at follow-up.

CONCLUSION

The Latarjet and ICBGT procedures for the treatment of anterior shoulder instability with glenoid bone loss showed no difference in clinical and radiologic outcomes except for significantly worse internal rotation capacity in the Latarjet group and frequently noted donor-site sensory disturbances in the ICBGT group.

Results of the Latarjet coracoid bone block procedure performed by mini invasive approach

INTRODUCTION

The coracoid block technique described by Latarjet was modified by Patte and Walch in order to increase the glenoid surface. Saragaglia further modified this technique and described a minimally invasive approach which allows faster post-operative recovery. The aim of this study was to evaluate the medium-term functional and radiological results of this technique.

METHODS

This is a single surgeon cohort of 40 shoulders in 38 patients (32 men, 6 women) with an average age of 34.5 years operated on between January and December 2014. The skin incision was 3 to 6 cm long allowing the bony block to be passed under the subscapularis tendon without sectioning it and to be placed in lying position. The bone block was fixed with a 6.5 cancellous screw or a 7.0 cannulated screw.

RESULTS

At an average follow-up of 48 months, there were no recurrent dislocations. The average WOSI score was 42, the average Constant score was 95 corrected to 97% and the average SSV was 97. Visual analogue scores were 0 at rest and 0.6 with activity. The bone block healed in 92.5% of cases. It was flush with the edge of the glenoid in 84% of cases, lateralised in 10% and medialised in 6% of cases. Mean internal rotation power was 12 kg in the operated shoulder compared with 9 kg in the non-operated shoulder.

CONCLUSION

The treatment of recurrent anterior shoulder instability by mini invasive Latarjet gives excellent medium-term functional results. The rate of recurrent dislocation in this series was zero and internal rotation power was well preserved. This is an excellent alternative to arthroscopic procedures which are yet to demonstrate their superiority over open surgery.