Complications after open Latarjet procedure: influence of arm positioning on musculocutaneous and axillary nerve function.

BACKGROUND: Alterations in the anatomical relationships of the musculocutaneous (MCN) and axillary nerves and the influence of arm positioning on these relationships after a Latarjet procedure have been demonstrated in the cadaver, but there are no studies in the literature that establish if there is any neurophysiological repercussion. METHODS: We retrospectively identified 24 patients with a primary or revision open Latarjet procedure. A prospective clinical (Constant-Murley, Rowe and Walch-Duplay and active range of motion), radiographic (with CT), and electrodiagnostic evaluation was made at the most recent follow-up. RESULTS: Nonunion occurred in four patients (22%); there were, as well, one case of partial coracoid reabsorption (5%) and two (11%) with mild glenohumeral osteoarthritis. In the anatomical position, we found no alterations in the musculocutaneous nerve and two cases (11%) in the axillary nerve slight motor unit loss. In the risk position, 11 cases (61%) had neurophysiological involvement (36% had neurophysiological changes in the musculocutaneous nerve and 64% in the axillary nerve). No differences between patients with or without neurophysiologic changes were found: Constant 87/83; Rowe 89/90; Walch-Duplay 84/78; Forward elevation 175º/170º, abduction 165°/175°; external rotation 48°/45°. CONCLUSION: The rate of clinical electromyographic changes in the axillary and MCN in the abducted and externally rotated arm position (risk dislocation position) is higher than in neutral position. Nonunion of the coracoid process must play a role in these neurophysiological changes. Although in the medium-term they don't have clinical impact, further randomized prospective studies with a larger sample size are necessary to determine their true repercussion. LEVEL OF EVIDENCE: Level IV.

Dislocation after reverse total shoulder arthroplasty using contemporary medialized modular systems. Can we still consider it such a frequent complication?

INTRODUCTION: Improvement in reverse total shoulder arthroplasty (RTSA) prosthesis and technique has reduced the initially high complication and revision rates associated with this implant. However, instability continues to be a leading cause of reoperation after RTSA, being related in previous studies with medialized designs. The aim of this study was to determine the dislocation rate with the employment of two medialized modular systems of RTSA in our institution. MATERIALS AND METHODS: A retrospective review of two different modular systems of RTSA (SMR Modular Shoulder System and Delta XTEND Reverse Shoulder) was performed between 2009 and 2017 with a minimum 3-year follow-up. Baseline demographic, clinical (Constant, ASES and ROM), and radiographic data were collected. Characteristics of postoperative instability cases were also evaluated. RESULTS: 237 primary RTSA (41% SMR/59% Delta) and 34 revision RTSA (44% SMR/56% Delta) with a mean follow-up of 75.6 ± 5.2 months (79.2 SMR/86.3 Delta, p = .586) were included in the present study. Indications for primary RTSA were osteoarthritis, rotator cuff tear arthropathy and massive irreparable rotator cuff tear (64%), acute fracture (32%), and fracture sequelae (4%). Subscapularis tendon was always repaired in degenerative pathology and tuberosities reattached in traumatic cases. The mean age of the global series was 76.5 ± 5.3 years (75.8 SMR/78.6 Delta, p = .104) with a mean Constant/ASES score at final follow-up of 68.5 ± 4.3/72.9 ± 20.3 (71/68 SMR and 69/74 Delta, p = .653 and .642). Only 2 patients (one acute fracture and one fracture sequelae) suffered an early postoperative anterior dislocation (before 3 months) which represents a rate of .84% in primary cases and .73% including revision surgery. Closed reduction manoeuvres were not successful, and both patients required revision surgery. At the end follow-up, both were stable and had no further dislocations. CONCLUSION: The dislocation rate after RTSA with the employment of two contemporary modular systems with a medialized centre of rotation is extremely low, especially when compared with the previously published series with the original Grammont design. Acute fracture and fracture sequelae were the main diagnoses associated with this instability. The reasons for the low dislocation rate are multifactorial, but the improvement in the baseplate position according to the more recent standards of "ideal position" and technical aspects such as subscapularis repair or tuberosity reattachment in fractures probably play an important role in this aspect.

Complications with the clavicle hook plate after fixation of Neer type II clavicle fractures.

BACKGROUND AND PURPOSE: There is no consensus on the optimal surgical procedure for treating Neer type-2 distal clavicle fractures. Hook plates provide better stability than other fixation methods for small fragments but have been related to multiple complications. METHODS: Retrospective study on patients operated for Neer type-2 fractures using a hook plate. At the time of the study, we performed functional (UCLA and Constant scales) and radiographic (coracoclavicular distance CCD) evaluation and ultrasound assessments of the condition of the rotator cuff. RESULTS: Twenty-four patients were included in the study, with a mean age of 43 years (18-81) and a mean follow-up of 40.4 months (22-67). All the fractures healed, except one. The plate was removed at a mean of five  months (3-13). The Constant score was 85.7 and the UCLA score was 32. The mean increase in CCD at final follow-up was 9.6% ± 7.2% (range 1.9-54.3%) compared with the uninjured side. Nine patients showed acromioclavicular arthrosis (only one case was symptomatic), and 12% showed subacromial osteolysis. No acromion fractures were recorded. The implant failed in three cases due to medial movement of the material, and we found one peri-plate fracture. CONCLUSIONS: The use of hook plates in this particular type of fracture provides high consolidation rates and good functional outcomes, irrespective of the fracture subtype. However, it is essential to select the correct length and depth of the hook to prevent complications such as medial movement of the implant. Ultrasound assessment showed that rotator cuff injury is not a common complication if the implant is removed as soon as the fracture has consolidated.