BACKGROUND: In patients with traumatic posterior shoulder instability, little is known about the precise location and size of the reverse Hill-Sachs lesion.
METHODS: Forty-nine shoulders of 47 patients with traumatic posterior instability were included in this study based on the following inclusion criteria: (1) a primary or recurrent traumatic posterior shoulder dislocation and (2) the initial event being caused by trauma. Patients were excluded if they had (1) no history of trauma, (2) prior shoulder surgery, (3) no computed tomographic (CT) examination, or (4) were seizure cases. Three-dimensional images of the humerus reconstructed from CT images were reviewed using an image analysis software. The location and size of the reverse Hill-Sachs lesion were measured and described on a clock face on the humeral head.
RESULTS: The reverse Hill-Sachs lesion was observed in 25 of 49 shoulders (51%). The reverse Hill-Sachs lesions were located between 1:37 and 2:48. The depth of the reverse Hill-Sachs lesion (mean ± standard deviation) was 5.8 ± 2.2 mm. The extent of the reverse Hill-Sachs lesion was 35° ± 12°. The average orientation of the reverse Hill-Sachs lesion, represented by an angle measured from the 12 o\'clock position, was 64° ± 12° and pointing toward 2:09 on a clock face. The mean length and width of reverse Hill-Sachs lesions were 9.7 ± 4.7 mm and 11.1 ± 3.6 mm, respectively.
CONCLUSIONS: The reverse Hill-Sachs lesion was a semicircular compression fracture located on the anteromedial aspect of the humeral head. Compared with shoulders with anterior shoulder instability, the humeral defect was smaller and located more inferiorly in shoulders with posterior instability.

UNASSIGNED: Multiple treatment options for locked posterior dislocation of the shoulder (LPDS) have been described, including the modified McLaughlin procedure. The purpose of this review, therefore, was to perform a systematic review of the literature to synthesize the available data reporting on the clinical and radiographic outcomes of patients undergoing the modified McLaughlin procedure for the treatment of LPDS.
UNASSIGNED: A systematic review of the PubMed Central, MEDLINE, Embase, Scopus, Web of Science, and Cochrane Library databases from inception through January 2023 was performed. Outcomes studies reporting on clinical and radiographic outcomes in patients undergoing the modified McLaughlin procedure for LPDS were included. Postoperative complications and episodes of recurrent instability were noted.
UNASSIGNED: A total of 1322 studies were initially identified, of which 9 were deemed eligible for inclusion in our review. Among included studies, a total of 97 shoulders (96 patients) with a mean age of 37.7 years (range, 26-51) were identified. The most common mechanisms of injury included trauma, seizure, and electrocution. Reverse Hill-Sachs lesions ranged in size from 20% to 50% of the humeral head articular surface. At final follow-up, the weighted mean University of California at Los Angeles shoulder score, Constant-Murley Score, American Shoulder and Elbow Surgeons shoulder score, and visual analog scale for pain score were 29 (range, 27-31), 75 (range, 65-92), 92 (range, 83-98), and 1.9 (range, 1-2.4), respectively. Postoperative Constant-Murley Score and University of California at Los Angeles scores were highest in the one study reporting exclusively on treatment during the acute period. Weighted mean postoperative forward flexion, abduction, external rotation, and internal rotation were 154° (range, 102-176), 144° (range, 118-171), 64° (range, 44-84), and 47° (range, 42-56), respectively. Osteointegration of the lesser tuberosity was noted in all patients at the final follow-up. Postoperative complications occurred in one patient (1.0% of cohort); a screw migration successfully treated with operative removal. Recurrent instability was noted in two epileptic patients (2.1% of cohort).
UNASSIGNED: The literature surrounding the use of the modified McLaughlin procedure for LPDS remains sparse. This review demonstrates that this procedure is associated with favorable clinical and radiographic outcomes with overall low rates of complication and recurrent instability, especially when the time from injury to surgery is minimized. These findings illustrate that in patients presenting with LPDS and a reverse Hill-Sachs lesion between 20% and 50% of the humeral head articular surface, the modified McLaughlin procedure is a safe and effective treatment option.

UNASSIGNED: Posterior glenohumeral joint dislocations are uncommon injuries. The disease often goes undiagnosed and untreated despite positive clinical signs. In the event of a large humeral bone defect, the outcome may be worse.
UNASSIGNED: This case report presents a 47-year-old man with a 2-year-old locked posterior shoulder dislocation with a large segmental bone defect involving 40% of the humeral head\'s articular surface. We decided to treat the patient with an open reduction of the shoulder dislocation and reconstruction of the articular surface with iliac crest autograft. We observed an improvement in shoulder mobility and range of motion on all planes, which were beneficial to the patient\'s daily activities; at follow-up, no pain was reported.
UNASSIGNED: Our case report demonstrates that locked posterior shoulder dislocations with a large bone defect and viable humeral head can be treated using an autograft. This will result in optimal clinical results and avoid early prosthetic replacement surgery. Autograft may be a preferred method in the presence of economic constraints or due to the unavailability of allografts or implants.

Introduction: Irregular bone defects of the humerus are common in clinical practice, but there are fewer reported cases of irregular humeral defects accompanied by shoulder joint \"locking\" dislocation and reverse Hill-Sachs injury caused by an electric shock. The choice of treatment for such cases is closely related to the extent of shoulder joint function recovery. This is a case report of a 60-year-old male patient who suffered from a shoulder joint \"locking\" dislocation with accompanying reverse Hill-Sachs injury due to muscle contraction after being electrically shocked at work. The patient was treated with a 3D-printed custom humeral head prosthesis for the treatment of the shoulder joint \"locking\" dislocation and reverse Hill-Sachs injury. Case presentation: A 60-year-old male patient, working as a construction worker, presented to our emergency department with right shoulder pain and restricted movement for more than 30 min after an electric shock. Right humeral CT revealed a comminuted fracture of the right humeral head. D-dimer levels were significantly elevated at 3239.00 ng/mL, and oxygen partial pressure was slightly decreased at 68 mmHg. Treatment included emergency wound debridement and dressing for the electrical injury, cardioprotective measures, anticoagulation, and symptomatic management. After stabilizing the patient\'s condition, the patient underwent 3D-printed custom prosthesis-assisted partial replacement of the right humeral head and rotator cuff repair in the orthopedic department. Postoperatively, the patient\'s right shoulder joint wound healed well, and mobility was restored. Conclusion: This case report demonstrates that the use of a 3D-printed custom prosthesis for the treatment of irregular humeral bone defects caused by specific injury mechanisms, especially cases involving shoulder joint \"locking\" dislocation and reverse Hill-Sachs injury, can achieve precise bone defect repair, minimize surgical trauma, and provide superior outcomes in terms of postoperative functional rehabilitation.

Exposure of the humeral articular surface through an anterior approach to the shoulder for grafting humeral bone defects requires partial or complete detachment of the subscapularis tendon and traditionally is achieved through a subscapularis tenotomy, peel tuberosity osteotomy, or lesser tuberosity osteotomy. This case report presents a technique of performing a pedicled-lesser tuberosity osteotomy to allow adequate access for allograft reconstruction of a large reverse Hill-Sachs lesion after a traumatic posterior dislocation, to restore humeral head sphericity and prevent recurrent glenohumeral joint instability. The inferior subscapularis insertion is left intact leaving a periosteal sleeve and preserving the blood supply to the lesser tuberosity and humeral head, with the aim of improving healing of the osteotomy and preventing graft-related complications, such as resorption. Successful union of the pedicled-lesser tuberosity osteotomy and allograft was seen on a 6-month follow-upcomputed tomography scan, with adequate restoration of subscapularis function.

BACKGROUND: The primary aim of this study was to investigate bone loss in the glenoid with magnetic resonance imaging in posterior shoulder instability with only a labral tear.
METHODS: A total of 76 patients operated on because of posterior and anteroposterior shoulder instability only with a labral tear between 2006 and 2019 (n = 40 and n = 36, respectively) were included in this study. The instability type, a presence of an additional superior labrum anteroposterior (SLAP) lesion, the number of dislocations, and the magnetic resonance imaging-based measurements (the glenoid diameter and the bone defect size in the glenoid, the Hill-Sachs lesion [HSL] and the reverse HSL [rHSL] length, the angle and the arc length of HSL and rHSL, and the humerus head diameter and its area) were analyzed.
RESULTS: The size of the anterior glenoid defect, the rHSL measurements (length, angle, and arc length), and the ratio of the anterior glenoid defect size to the glenoid diameter were significantly higher for anteroposterior instability (P < .01) cases. There was no significant difference (P = .49, .64, and .82, respectively) for the presence of an additional SLAP pathology, the glenoid diameter, the posterior glenoid defect, and the ratio of the posterior glenoid defect size to the glenoid diameter in posterior and anteroposterior instability groups. The increased number of dislocations was associated with increased rHSL length and total arc length (P = .04 and .03, respectively). An additional SLAP lesion in posterior shoulder instabilities was not associated with the bone defect size (P = .29).
CONCLUSIONS: Although the posterior shoulder instability with only a labral tear is likely to cause a bone defect, we have shown that the instability is not expected to be caused by the bone defect. Therefore, this study points out that only soft tissue repair without considering the bone defect could be promising in this patient group.

A Hill-Sachs lesion, a posterolateral bony defect of the proximal humerus, occurs when the humerus head collides with the anterior region of the glenoid during an anterior shoulder dislocation. A posteriorly dislocated shoulder may cause a reverse Hill-Sachs lesion, which is a deficiency on the anteromedial part of the humeral head due to impaction. Avascular necrosis could result from this lesion if detection and repair are not carried out. The subscapularis tendon is separated from the smaller tuberosity using an open technique in the original McLaughlin procedure, which was initially described in 1952. In neglected cases of patients undergoing surgery after three weeks, there is no commonly accepted standard of care. Glenohumeral joint stabilization and early and full functional recovery are the two objectives of the procedure. This case report describes a modified McLaughlin surgery where the subscapularis tendon and lesser tuberosity are transferred to the reverse Hill-Sachs defect for stability. The clinical significance of our case report is that it accentuates the role of early detection and appropriate management of reverse Hill-Sachs lesion, which is often overlooked and missed in a case of posterior shoulder dislocation. The use of the modified McLaughlin procedure not only covers the defect with a bone chunk and the subscapularis tendon transfer over the head of the humerus but the stable fixation with the anchor and cannulated cancellous screw helps in early rehabilitation of the shoulder joint.

BACKGROUND: Posterior shoulder dislocation is an uncommon orthopaedics injury and is frequently missed or misdiagnosed, accounting for 2%-4% of all shoulder dislocations, and is associated with the reverse Hill-Sachs lesion. Once posterior shoulder dislocation develops into a chronic disease, it will bring a lot of trouble to the treatment, especially in repairing the humeral defects. Surgical strategies are also developing and innovating to deal with this injury, including transfer of subscapularis tendon or lesser tubercle, humeral rotational osteotomy, autogenous bone graft or allograft. Shoulder replacement seems to be the ultimate and only option when the injury becomes irreparable, although some studies have shown unsatisfactory follow-up results. Considering no gold-standard treatment for locked posterior shoulder dislocation, we described a novel modified McLaughlin procedure for locked chronic posterior shoulder dislocation and evaluated the functional outcomes.
METHODS: This study included five locked chronic posterior shoulder dislocation patients with an associated reverse Hill-Sachs lesion, in which the compression surface covered 30-40% of the humeral head. The mean period from injury to receiving surgery was 11.6 weeks (6-24 weeks). All five patients underwent the modified McLaughlin procedure, mainly divided into three steps, including open reduction, transfer of the partial lesser tuberosity and artificial bone to repair the reverse Hill-Sachs defects. The kernel technique was to fix the transferred tuberosity with two lag screws and strengthen it with two Ethibond sutures. The Constant-Murley score (CMS), the range of shoulder motion and the complications were recorded to assess and compare the functional situation of the shoulder postoperatively and postoperatively.
RESULTS: After an average of 19.8 months (12-30) of follow-up, the mean CMS improved to 85.8 ± 4.9 (79-91) compared with 46.0 ± 4.5 (40-52) preoperatively, which showed a significant difference (p = 0.001). In the final follow-up, all five patients showed no symptoms of shoulder instability, and there was no pain or limited activity in daily life, thus all patients were satisfied with the results.
CONCLUSIONS: Repairing the reverse Hill-Sachs lesion by transferring the partial lesser tuberosity combined with artificial bone fixed by lag screws and sutures can ensure shoulder stability and provide pain relief and good function in patients with locked chronic posterior shoulder dislocation associated with the humeral head defect.

BACKGROUND: It has not been clarified yet how much force is acting on the shoulder joint to create Hill-Sachs/reverse Hill-Sachs lesions which are commonly observed in patients with anterior or posterior shoulder instability. The purpose of this study was to determine the magnitude of force to create these bony lesions using cadaveric shoulders.
METHODS: Fourteen fresh-frozen cadaveric shoulders were used. Compression tests were performed using the universal testing machine. The specimens were randomly divided into two groups. In group A, the posterior humeral head (the bare area and articular cartilage) was first compressed against the anterior glenoid rim to simulate a Hill-Sachs lesion, followed by the anterior humeral head being compressed against the posterior glenoid rim. In group B, the same procedure was repeated in the reverse order. X-ray microcomputed tomography (microCT) was also performed.
RESULTS: The maximum compression force to create a Hill-Sachs lesion was 771 ± 214 N (mean ± SD) on the articular cartilage of the posterior humeral head, which was significantly greater than the force of 447 ± 215 N to create it on the bare area (P = 0.0086). Regarding the reverse Hill-Sachs lesions, the maximum compression force was 840 ± 198 N when it was created on the articular cartilage of the anterior humeral head, which was significantly greater than the force of 471 ± 100 N when it was created at the footprint of the subscapularis tendon (P = 0.0238). MicroCT showed multiple breakage of the trabecular bone.
CONCLUSIONS: A force to create a Hill-Sachs lesion or a reverse Hill-Sachs lesion was significantly greater when it was created on the humeral articular cartilage than at the non-cartilage area. Also, the force to create a reverse Hill-Sachs lesion was significantly greater than the one to create a Hill-Sachs lesion.

We present the case of a 71-year-old man who suffered a bilateral posterior fracture-dislocation of the shoulder after an idiopathic seizure. After immediate closed reduction, CT-scan images revealed bilateral anterior reverse Hill-Sachs lesion superior to 30 % of the articular humeral head. A surgical treatment was performed for reconstruction of segmental defects of the articular humeral heads followed by filling the defect using lesser tuberosity transposition. Early rehabilitation protocol was prescribed. After 14 months, the patient returned to normal daily activities with no complaint. Anatomical humeral head reconstruction and bone defect filling resulted in a good clinical outcome after posterior shoulder dislocation. It can be the treatment of choice for large humeral head defects, especially in younger patients with good bone stock.