Aim: To determine whether isolated lesions of the glenoid labrum or capsulolabral lesios influence anterior and inferior shoulder stability in a cadaver model that leaves all other glenohumeral structures, including the capsule, intact. Methods: Sequential arthroscopic resection of the labrum was performed with a motorized shaver in seventeen fresh cadaver shoulders. A capsulolabral dehiscence was created arthroscopically in another eleven fresh cadaver shoulders. The capsulolabral complex was divided into five zones: from superior to posterior. Inferior and anterior stability were tested before and after each cutting step. Results: The hyper-abduction test showed progressive increase in abduction with each step, with a maximum of 120° reached after removal of the labrum in all four zones or after detachment of all zones. Resection of the superior to inferior labrum maximally resulted in subluxation, but not in dislocation of the shoulder. Capsulolabral dehiscence of all but the posterior zones resulted in a locked (6/11) or a metastable (4/11) dislocation. In the other specimens the posterior zone needed to be detached as well for a metastable dislocation. Conclusion: Purely labral lesions and limited capsulolabral detachments do not seem to be sufficient to allow the humeral head to dislocate. Labral tears can therefore be debrided without consequences for shoulder stability. In the present study, a capsulolabral detachment in the antero-inferior zone (the typical Bankart lesion) does not allow the humeral head to dislocate. This leads us to suggest that associated lesions must exist in chronic instability

Aim: Retrospective evaluation of the clinical results of arthroscopic capsulolabral stabilisation using suture anchors with a mattress technique.

Materials and Methods: Sixty five consecutive procedures in sixty-two patients (50 male, 12 female) with mean age of 38 years (14–66) underwent capsulolabral stabilisation by the senior author between 2005 and 2008. There was a history of dislocation in 38 shoulders (58.4%), 16(42.6%) had recurrent and 6 bilateral instability, 27 patients (41.5% shoulders) presented with pain. Thirteen patients had gradual onset and 14 after an injury. The mean follow up was 29 months (14–54).

Results: Arthroscopic findings included three patients (5%) with glenoid bone loss more than 15%, Hill Sachs lesions greater than 20% in eighteen patients (27.6%) and six cases where the torn labrum was partially absent. Three shoulders had a panlabral tear (4.4%). A mean of 2.3 (1–4) anchors were used. The mean Rowe score was 92.3 (30–100) with 90% excellent or good and the mean Oxford Score was 41(16–48) with 89% excellent or good. All heavy manual workers returned to work in a mean of 15.4 weeks. Four professional athletes are back to preinjury level in a mean of twenty weeks. There were two (3%) failures with redislocation.

Conclusion: Reinforcement of labral repair with capsule plication is an effective means to treat shoulder instability with a 97% success rate and no exclusion criteria.

Purpose

The remplissage procedure may be performed as an adjunct to Bankart repair to address an engaging Hill-Sachs defect. Clinically, it has been reported that the remplissage procedure improves joint stability but that it may also restrict shoulder range of motion. The purpose of this biomechanical study was to examine the effects of the remplissage procedure on shoulder motion and stability. We hypothesized that the remplissage procedure would improve stability and prevent engagement but may have a deleterious effect on motion.

Aim: To study the contribution of humeral avulsion of the glenohumeral ligaments (HAGL) to shoulder instability. Methods: In fourteen fresh cadaver shoulders a selective cutting sequence was performed. After each section an abduction-external rotation manoeuvre with axial compression and translation was carried out to provoke dislocation. The resulting instability was graded on a scale of five, ranging from no translation to a locked dislocation. Results: Cutting of only the inferior glenohumeral ligament complex resulted at the most in increased translation, but not in subluxation. For subluxation to occur, at least the middle glenohumeral ligament needed to be cut. The entire humeral capsuloligamentous complex needed to be sectioned before subluxation or dislocation occurred. In half of the cases an additional lesion of the subscapularis or the latissimus dorsi is necessary to allow a locked antero-inferior dislocation. Conclusion: Extensive damage to the humeral side of the capsulo-ligamentous complex and, frequently, associated lesions of the subscapularis or latissimus dorsi muscles are necessary to allow dislocation. This might be the primary reason for the low incidence of HAGL observed in clinical series of shoulder instability

Glenohumeral joint injuries frequently result in shoulder instability. However, the biomechanical effect of cartilage loss on shoulder stability remains unknown. The aim of the current study was to investigate biomechanically the effect of two severity stages of cartilage loss in different dislocation directions on shoulder stability. Joint dislocation was provoked for 11 human cadaveric glenoids in seven different dislocation directions between 3 o'clock (anterior) to 9 o'clock (posterior) dislocation. Shoulder stability ratio (SSR) and concavity gradient were assessed in intact condition, and after 3 mm and 6 mm simulated cartilage loss. The influence of cartilage loss on SSR and concavity gradient was statistically evaluated. Between intact state and 6 mm cartilage loss, both SSR and concavity gradient decreased significantly in every dislocation direction (p≤0.038), except the concavity gradient in 4 o'clock dislocation direction (p=0.088). Thereby, anterior-inferior dislocation directions were associated with the highest loss of SSR and concavity gradient of up to 59.0% and 49.4%, respectively, being significantly higher for SSR compared to all other dislocation directions (p≤0.04). The correlations between concavity gradient and SSR for pooled dislocation directions were significant for all three conditions of cartilage loss (p<0.001). From a biomechanical perspective, articular cartilage of the glenoid contributes significantly to the concavity gradient, correlating strongly with the associated loss in glenohumeral joint stability. The highest effect of cartilage loss was observed in anterior-inferior dislocation directions, suggesting that surgical intervention should be considered for recurrent shoulder dislocations in the presence of cartilage loss

Osteochondral glenoid loss is associated with recurrent shoulder instability. The critical threshold for surgical stabilization is multidimensional and conclusively unknown. The aim of this work was to provide a well- measurable surrogate parameter of an unstable shoulder joint for the frequent anterior-inferior dislocation direction. The shoulder stability ratio (SSR) of 10 paired human cadaveric glenoids was determined in anterior-inferior dislocation direction. Osteochondral defects were simulated by gradually removing osteochondral structures in 5%-stages up to 20% of the intact diameter. The glenoid morphological parameters glenoid depth, concavity gradient, and defect radius were measured at each stage by means of optical motion tracking. Based on these parameters, the osteochondral stability ratio (OSSR) was calculated. Correlation analyses between SSR and all morphological parameters, as well as OSSR were performed. The loss of SSR, concavity gradient, depth and OSSR with increasing defect size was significant (all p<0.001). The loss of SSR strongly correlated with the losses of concavity gradient (PCC = 0.918), of depth (PCC = 0.899), and of OSSR (PCC = 0.949). In contrast, the percentage loss based on intact diameter (defect size) correlated weaker with SSR (PCC=0.687). Small osteochondral defects (≤10%) led to significantly higher SSR decrease in small glenoids (diameter <25mm) compared to large (≥ 25mm) ones (p ≤ 0.009). From a biomechanical perspective, the losses of concavity gradient, glenoid depth and OSSR correlate strong with the loss of SSR. Therefore, especially the loss of glenoidal depth may be considered as a valid and reliable alternative parameter to describe shoulder instability. Furthermore, smaller glenoids are more vulnerable to become unstable in case of small osteochondral loosening. On the other hand, the standardly used percentage defect size based on intact diameter correlates weaker with the magnitude of instability and may therefore not be a valid parameter for judgement of shoulder instability

The laterjet procedure is an important option in both primary and revision surgeries, especially in anterior shoulder instabilities that progress with glenoid bone loss. 12 patients who had a history of unsuccessful arthroscopic bankart repair and who underwent laterjet procedure in Ankara Atatürk Research and Training Hospital between 2013 and 2017 were included in the study and the patients were evaluated retrospectively. The mean age of the patients was calculated as 27.7 (range 21 to 38 years). Rowe and Walch-Duplay scores and operated shoulder (OS)-healthy shoulder (HS) range of motion (ROM) measurements were used to evaluate patients clinically and functionally. The mean follow-up time of the patients was calculated as 5.5±1.8 years. Firstly, no dislocation history was recorded in any patient afer the laterjet procedure. The mean Rowe score was calculated as 82.5 (range 60–100). Accordingly, 8 patients had excellent result, 3 patients had good result and 1 patient had fair result. The mean Walch-Duplay score was 81.4 (range 55–100). It was determined as excellent result in 6 patients, good result in 4 patients and fair result in 2 patients. Another data, joint ROM of the OS-HS of patients are shown in the table. There was some limitation in OS compared to the HS. p<0.05 value was accepted as statistically significant. While there was a statistically significant difference in external rotation (OS:35.2º, HS:56.4º)(p=0.003), internal rotation (OS:65.7º, HS:68.1º)(p=0.008) and flexion (OS:171.2º, HS:175.9º)(p=0.012) degrees but there was no statistically significant difference in abduction degrees (OS:164.3º, HS:170.4º) (p=0.089). In radiological evaluation, partial graft resorption was detected in 1 patient, but it was asymptomatic. The osteoarthritis which is one of the complications of laterjet procedure, was not detected radiologically. There are some limitations of the study. Firstly, it is a retrospective study. Secondly, the demographic features of the patients such as age, gender, profession and dominant hand are excluded. Thirdly, the mean follow-up time is not too long. Finally, some of the scales filled in are based on the patient's declaration, which may not yield sufficient objective results. In conclusion, the laterjet procedure is a suitable and reliable technique even for revision surgery in the treatment of anterior shoulder instability. It gives positive results in terms of shoulder stability and function. The major disadvantage was found to be the limitation of external rotation. Longer follow-up is needed for another outcomes and late complications, such as osteoarthritis. For any figures or tables, please contact the authors directly

Objectives. The bony shoulder stability ratio (BSSR) allows for quantification of the bony stabilisers in vivo. We aimed to biomechanically validate the BSSR, determine whether joint incongruence affects the stability ratio (SR) of a shoulder model, and determine the correct parameters (glenoid concavity versus humeral head radius) for calculation of the BSSR in vivo. Methods. Four polyethylene balls (radii: 19.1 mm to 38.1 mm) were used to mould four fitting sockets in four different depths (3.2 mm to 19.1mm). The SR was measured in biomechanical congruent and incongruent experimental series. The experimental SR of a congruent system was compared with the calculated SR based on the BSSR approach. Differences in SR between congruent and incongruent experimental conditions were quantified. Finally, the experimental SR was compared with either calculated SR based on the socket concavity or plastic ball radius. Results. The experimental SR is comparable with the calculated SR (mean difference 10%, . sd. 8%; relative values). The experimental incongruence study observed almost no differences (2%, . sd. 2%). The calculated SR on the basis of the socket concavity radius is superior in predicting the experimental SR (mean difference 10%, . sd. 9%) compared with the calculated SR based on the plastic ball radius (mean difference 42%, . sd. 55%). Conclusion. The present biomechanical investigation confirmed the validity of the BSSR. Incongruence has no significant effect on the SR of a shoulder model. In the event of an incongruent system, the calculation of the BSSR on the basis of the glenoid concavity radius is recommended. Cite this article: L. Ernstbrunner, J-D. Werthel, T. Hatta, A. R. Thoreson, H. Resch, K-N. An, P. Moroder. Biomechanical analysis of the effect of congruence, depth and radius on the stability ratio of a simplistic ‘ball-and-socket’ joint model. Bone Joint Res 2016;5:453–460. DOI: 10.1302/2046-3758.510.BJR-2016-0078.R1

Aims

The liner design is a key determinant of the constraint of a reverse total shoulder arthroplasty (rTSA). The aim of this study was to compare the degree of constraint of rTSA liners between different implant systems.

Background:. Individuals with large Hill-Sachs lesions may be prone to failure and reoccurrence following standard arthroscopic Bankart repair. Here, the Remplissage procedure may promote shoulder stability through infraspinatus capsulo-tenodesis directly into the lesion. Little biomechanicaldata about the Remplissage procedure on glenohumeral kinematics, stability, and range of motion (ROM) currently exists. Questions/purposes:. What are the biomechanical effects of Bankart and Remplissage repair for large Hill-Sachs lesions?. Methods:. Six cadaveric shoulders were tested using a custom shoulder testing system. ROM and glenohumeral translation with applied loads in anterior-posterior (AP) and superior-inferior (SI) directions were quantified at 0° and 60° gleno-humeral abduction. Six conditions were tested: intact, Bankart lesion, Bankart with 40% Hill-Sachs lesion, Bankart repair, Bankart repair with Remplissage, and Remplissage repair alone. Results:. Humeral external rotation (ER) and total range of motion (TR) increased significantly from intact after the creation of the Bankart lesion at both 0° abduction (ER +27.0°, TR +35.8°, p < 0.05) [Fig 1] and 60° abduction (ER +9.5°, TR +30.7°, p < 0.05) [Fig 2], but did not increase further with the addition of the Hill-Sachs lesion. The Bankart repair restored range of motion to intact values 0° abduction at addition of the Remplissage repair did not significantly alter range of motion from the Bankart repair alone. There were no significant changes in AP or SI translation between Bankart repair with and without Remplissage compared to the intact specimen. Conclusions:. The addition of the Remplissage procedure for treatment of large Hill-Sachs lesions had no statistically significant effect on ROM or translation for treatment for large Hill-Sachs lesions. Clinical Relevance: The Remplissage technique may be a suitable option for engaging Hill-Sachs lesions. Further clinical studies are warranted

Purpose of the study: The purpose of this study was to report the clinical and radiographic outcomes a minimum five years after Latarjet-Patte treatment for recurrent traumatic anterior instability of the shoulder in rugby players. It was hypothesised that the Latarjet-Patte procedure fulfils the needs for shoulder stability in rugby players with anterior instability. Material and methods: Thirty-four players (37 shoulders) were included. Mean age was 23.4 years (17–33). A bone lesion of the glenoid was noted in 73% of the shoulders, a humeral defect in 68%. Results: Mean follow-up was 144 months (range 68–237). There was no recurrence (dislocation or subluxation). Apprehension persisted in five patients (14%). Sixty-five percent of the patients resumed playing rugby. Only one patient interrupted his sports activities because of the operated shoulder. The Walch-Duplay and Rowe scores were 86 and 93 points on average. The satisfaction rate was 94%. The block healed in 89% of shoulders (3 fractures, 1 nonunion). Twenty-six shoulders (70%) were free of degenerative disease, 11 shoulders (30%) presented stage 1 lesions. Discussion: In rugby players, anterior instability exhibits characteristic bone lesions of the humerus and glenoid which can be identified as risk factors for recurrent instability. The Latarjet-Patte procedure provides a stable shoulder allowing resumption of rugby player for most patients with no long-term degradation of the shoulder joint. These results are in favour of our strategy to propose the coracoids block systematically for recurrent anterior instability in rugby players

Aims

Recurrent dislocation is both a cause and consequence of glenoid bone loss, and the extent of the bony defect is an indicator guiding operative intervention. Literature suggests that loss greater than 25% requires glenoid reconstruction. Measuring bone loss is controversial; studies use different methods to determine this, with no clear evidence of reproducibility. A systematic review was performed to identify existing CT-based methods of quantifying glenoid bone loss and establish their reliability and reproducibility

Purpose of the study: Posterior fracture-impaction of the humeral head (Hill-Sachs defect or Malgainge notch) is a well-known factor of failure for arthroscopic shoulder stabilisation procedures. Recently, Wolf proposed arthroscopic posterior capsulodesis and tenodesis of the infraspinatus, or what we call in French Hill-Sachs Remplissage (filling). We hypothesised that capsule and tendon healing within the bony defect could explain the efficacy of this arthroscopic technique. Material and methods: Prospective clinical study of a continuous series. Inclusion criteria:. recurrent anterior instability (dislocation or subluxation);. isolated “engaged” humeral defect;. Bankart arthroscopy and Hill-Sachs remplissage;. arthroCT or MRI at least 6 months after surgery. Exclusion criteria:. associated bone loss in the glenoid;. associated rotator cuff tear. Twenty shoulders (20 patients) met the inclusion and exclusion criteria and underwent Hill-Sachs remplissage. Four orthopaedic surgeons evaluated independently the soft tissue healing in the humeral defect. Mann-Whitney analysis was used to search for a link between rate of healing and clinical outcome. Results: Filling of the humeral defect reached 75 to 100% in 16 patients (80%°; it was 50–75% in 4 patients. Healing was never noted less than 50%. The short-term clinical outcome (mean follow-up 11.4 months, range 6–32) showed an excellent results as assessed by the Constant score (mean 92±8.9 points) and the Walch-Duplay score (91 points). The subjective shoulder value (SSV) was 50% preoperatively and 89% at last follow-up. There were no cases of recurrent instability. This study was unable to establish a relationship between minor healing and less favourable clinical outcome. Discussion: This study confirmed our hypothesis that arthroscopic Hill-Sachs remplissage provides a high rate of significant healing in a majority of patients. Capsule and tendon healing in the humeral defect yields significant shoulder stability via at least two mechanisms:. prevention of defect engagement on the anterior border of the glenoid and. posterior force via improved muscle and tendon balance in the horizontal plane. Further mid- and long-term results will be needed to establish a confirmed correlation between healing and clinical outcome

Purpose of the study: The purpose of this retrospective clinical and radiographic study was to analyse the long-term results obtained after Patte’s triple locking procedure for the treatment of anterior instability of the shoulder joint. Material and methods: A questionnaire was sent to 574 patients who underwent the procedure performed by the same senior operator from 1986 to 2006. Variables studied wer the Walch-Duplay score (with pain score), patient satisfaction, postoperative complications and radiographic aspect. Results: One hundred fifty patients (26%) responded and sent three radiographs. There were 107 men and 43 women, mean age 28.6±8.7 years (range 16–57). Mean follow-up was 14.6 years (range 2.8–22.6). One hundred seventeen patients (78%) were reviewed with follow-up greater than 10 years. Two patients (1.3%) experienced recurrent anterior instability; no revision was required. The Walch-Duplay scores were excellent or good in 146 patients (97.3%); 53% of patients were pain free; 34% had episodic pain, 9% moderate to mild pain and 4% severe pain. Resumption of sports activity was noted by 85% of patients. Overall, 79% of patients were very satisfied, 18% satisfied, and 3% not satisfied. Postoperative complications (2%) were one case each of infection, transient paresis of the musculocutaeous nerve, and superficial venous thrombosis. There were radiographic signs of an anomaly of the coracoids block in 13 patients (8%); non-union (n=3), lysis (n=4) fracture (n=2), migration (n=1), fracture of the ceramic washer (n=3). The block or washer overhang was noted in 19 patients (12.7%). Centred osteoarthritis was noted in 31% of patients (25% Samilson 1, 4% Samilson 2, 2% Samilson 3). There were two factors associated with long-term degenerative disease: age > 40 at surgery (p=0.02 and block overhang (p< 0.01). Discussion: Patte’s triple locking procedure is an open procedure for the treatment of anterior shoulder instability. The technique is very minute and specific postoperative rehabilitation is needed. In these conditions, the operation is effective, providing good control of shoulder stability and allowing resumption of sports activities with a low complication rate. This study shows that long-term degenerative disease can be decreased if the patient undergoes surgery before the age of 40 years and if the coracoids block does not overhang

Introduction: Various surgical methods have been described to manage the problem of recurrent anterior dislocation of the shoulder. Older procedures Putti-Platt’s, Magnuson-Stack’s or Bristow;’s and Boytchev’s repair are not used today due to a high percentage of failure of 7%–17% incidence of recurrence associated with limited ROM. However, in the last decade the goal of treatment has changed. It is directed now towards restoration of normal function with full ROM of the affected shoulder, based mainly on arthroscopic stabilization or on “open” Neer’s capsular shift procedures combined with Bankart’s repair. However, during the last few years there are more and more papers dealing with a surprising unexpected high number of patients with shoulder instability following arthroscopic repair. The purpose of this study is to review the long term results of “open” Neer’s capsular shift procedure. Materials & Methods: This is a presentation of 87 (78M; 9F) consecutive patients, 19 to 47 year old (mean 23 Y) with a length of follow-up of 4Y–15Y (mean 6Y). 45 of them with traumatic recurrent anterior dislocation of the shoulder had a capsular shift procedure according to Rockwood’s modification. In 42 other patients that had a multidirectional instability with proved dislocations of the affected shoulder a Protzman’s modified capsular shift procedure was used. Results: 82/87 patients had a stable shoulder without recurrent dislocation. 3 patients had an episode of traumatic shoulder dislocation within 2 months following operation. Two other patients of 42 with multidirectional instability had a recurrence of traumatic dislocation. One patient developed partial brachial plexus injury, most probably due to traction of the affected limb following operation. 78/87 had at follow-up normal shoulder function with full ROM, and the remaining 9 patients had only a slight limitation in shoulder abduction and in external rotation. Conclusions: Based on this study, it is suggested that capsular shift procedure is an excellent method for repair of recurrent anterior shoulder dislocation, preferable to the “older” procedures, and allows restoration of shoulder stability with better functional results. This is suitable mainly for patients with structural hyperlaxity and multidirectional instability, whereas arthroscopic stabilization might be used in patients with true traumatic instability

Purpose of the study: Depending on the series, fractures of the anteroinferior glenoid labrum have been reported in 3% to 90% of patients with anterior shoulder instability. These fractures disrupt the physiological glenoid concavity and shorten the effective length of the glenoid arch. Indications for treatment depend on the size of the fragment and range from osteosynthesis to resection or suture. We hypothesized that these lesions could be treated arthroscopically (Bankart procedure with fragment suture). The purpose of this work was to analyze clinical and radiological outcome observed in nine patients with anterior instability associated with significant glenoid fracture. Material and methods: This was a monocentric study of a continuous series of nine glenoid fractures associated with anteromedial dislocation in nine patients (three women and six men), mean age 35.5 years (range 17–75 years). Preoperatively, all of the fractures were considered to involve more than 25% of the glenoid surface. After detaching the capsulolabral lesion with the bony fragment and avivement of the anterior border, the Bankart procedure was performed with anchors and resorbable sutures. The shoulder was strapped for six weeks with passive rehabilitation (pendulum movements) initiated early. Results: Mean follow-up was 27 months (range 12–48 months). There were no cases of recurrent instability. Seven patients were very satisfied and two were satisfied. Eight patients were able to resume their sports activities at the same level. Apprehension developed in all patients. At last follow-up, joint motion was normal for eight of the nine patients, the Duplay score was 100 for eight patients and 45 for one. All bony lesions healed in an anatomic position (six analyzed with plain x-rays and three with CT scan). Discussion and conclusion: This short series demonstrates that glenoid fractures can be treated arthroscopically with concomitant treatment of the capsulolabroligament complex in order to reconstruct the glenoid arch, an essential element for restoring shoulder stability. It is thus necessary to identify bony lesions preoperatively to determine the most appropriate therapeutic approach. A long-term follow-up will be useful to assess the rate of recurrent instability and validate this therapeutic option

Thermal capsular shrinkage presents the prospect of reducing redundant capsule, and therefore may be a suitable method of treating capsular-type instability. A prospective study of fifty-four consecutive patients (58 shoulders) treated exclusively with radiofrequency capsular shrinkage for atraumatic instability. The mean Rowe score improved from 33.1 to 74.1 points at followup of up to 48 months. Twenty of the fifty-eight shoulders had recurrence instability. Recurrent instability was related to the type of instability: 76.9% for voluntary instability, 30.3% for involuntary instability and none of 12 shoulders for instability/impingement pain. Recurrence was related as well to previous instability surgery (70%). The outcome was not related to the direction of instability, type of radiofrequency probe used, age of patient or ligamentous laxity. Twenty-two (57.9%) of thirty-eight patients returned to their pre-instability level of sporting activity. By using repeated RF treatments for the failed thermal shrinkage cases the failure rate was reduced from (20/58) 34.5% to (13/58) 22.4% and cumulative changes were seen on electron microscopy. These results are comparable to some of the results for open inferior capsular shift for patients with multidirectional instability with substantial less morbidity. The application of the minimal effective energy is controlled according to the tissue response without any charring or burning effect to the tissue. No scar was seen in repeated arthroscopies, or in electron microscopy studies. Thermal shrinkage does not negatively affect a later open stabilisation, but rather may provide better conditions for secure open surgery. We have found significant improvement in proprioception following thermal shrinkage treatment. We believe that by re-tensioning the proprioceptors they begin to fire off at lesser degrees of movement, and that there is a greater dynamic muscular contribution to shoulder stability. When using the correct technique for the right indications, Radiofrequency thermal shrinkage is a viable alternative to open inferior capsular shift in patients with capsular type of instability

Background: The Inferior Glenohumeral Ligament (IGHL) has a well known mechanical and propioceptive relevance in shoulder stability. The interrelation of the IGHL anatomical disposition and innervation has not actually been described. The studys purpose was to determine the IGHL innervation patterns and relate them to dislocation. Material & methods: Forty-five embalmed and 16 fresh-frozen human cadaveric shoulders were studied. Massons Trichrome staining was used to detail the intra-ligamentous nerve fibre arrangements. Neural behaviour of the articular nerves was studied dynamically at the apprehension position and while anteroinferior dislocation of the shoulder joint was performed. Results: The anatomy of the IGHL was clearly defined. However, in 7 out of 61 cases the anterior band was only a slight thickening of the ligament. It averaged 34 mm (range, 28 to 46 mm) in length. The posterior band was only seen in 40.98 % of the cases. The axillary nerve provided IGHL innervation in 95.08 % of the cases. We found two distinct innervation patterns originating in the axillary nerve. In Type 1 (29.5 % of the cases), one or two collaterals later diverged from the main trunk to enter the ligament. Type 2 (65.57%) showed innervation to the ligament provided by the posterior branch for three to four neural branches. In both cases, these branches enter the ligament near the glenoid rim and at 7 oclock position (right shoulder). The shortest distance to the glenohumeral capsule was noted at 5 oclock position. The radial nerve (Type 3 innervation pattern) provided IGHL innervation in 3.28 % (2 specimens). Microscopic analysis revealed wavy intraligamentous neural branches. The articular branches relaxed and separated from the capsule at external rotation and abduction and stayed intact after dislocation. Conclusions: The current results showed the IGHL to have three different innervation patterns. The special neural anatomy of the IGHL suggested it was designed to avoiding denervation when dislocated. This might contribute to understand why the neural arch remains unaffected after most dislocations. To our knowledge this is the first work that clearly describes specimens in which the main innervation of the IGHL is provided by the radial nerve. Knowledge of the neural anatomy of the shoulder will clearly help in avoiding its injury in surgical procedures

Purpose: Posterior instability of the shoulder requires surgical treatment in involuntary forms and after failure of functional treatment. As for anterior instability, a bone block can be fashioned from an iliac graft or a pediculated graft harvested from the acromion. This retrospective analysis concerned the results obtained in eighteen consecutive cases. Material and methods: This series included ten men and eight women, mean age 26 years (15–42) at time of surgery. Fourteen (77%) practised sports activities including four at competition level. Symptoms had persisted for four years on the average. For three patients (16%) posterior instability was expressed by recurrent luxation subluxation. For nine patients (50%) posterior subluxation was a common involuntary event. Six patients suffered from painful shoulders due to an unrecognised posterior instability accident. Diagnosis of posterior instability was establised by arthroscopy in seven patients (39%). For nine shoulders the intervention consisted in a screwed posterior iliac block associated with a tension procedure on the capsule (group 1). For the other nine shoulders the block was harvested from the acromion and pediculated on the deltoid (group 2). Results: Mean follow-up for all patients was eight years. The Duplay score was 75 points at last follow-up. Twelve patients (85% of the athletes) were able to resume their sports activities, half at the same level. Nine patients were pain free. Six patients (33%) had persistent apprehension but did not present true recurrence at physical examination. The Duplay score was 69.4 points in group 1 (follow-up 12 years) and 82.2 points in group 2 (follow-up three years). Thirteen patients (77%) did not have any sign of joint degeneration at last follow-up. One patient had advanced stage IV degeneration related to an intra-articular screw. All patients felt their shoulder had been improved by surgery and one third were disappointed with the results. Discussion: Use of a posterior block is an effective treatent for posterior instability giving results comparable with those obtained with anterior blocks in terms of shoulder stability, pain, recovery of motion, and subjective outcome. This procedure favours joint degeneration less than anterior stabilisation. Results obtained with pediculated acromial blocks are encouraging