Proximal humeral fractures (PHFs) refer to fractures involving the area from the humeral head to 2 to 3 cm away from the surgical neck of the humerus. They usually involve the surgical neck, large and small nodules, the anatomical neck, or the humeral head. Some patients also experience humeral head dislocation, and a few cases are accompanied by brachial plexus nerve injury. Epidemiological studies have shown that its incidence accounts for 4% to 10% of all fractures. Among elderly patients, its incidence rate is second only to hip fractures and distal radius fractures, and it is the seventh most common type of fracture in adults. With age, the phenomenon of osteoporosis, driven by physiological and pathological changes such as negative calcium balance and the degeneration of bone tissue microstructure, becomes increasingly evident. At the same time, the elderly often have geriatric syndromes such as ataxia and muscle strength decline, which can lead to PHFs when they suffer from low-energy injuries (such as falls, etc.). For stable fractures without obvious displacement, satisfactory therapeutic effects can be achieved through non-surgical methods such as suspension fixation and early functional exercise. However, for complex fractures with significant displacement, surgical treatment is usually adopted. There are numerous fixation techniques for PHFs. Dimakopoulos et al. believe that the bone suture fixation technique balances efficacy and cost-effectiveness. The Picker-needle fixation technique can prevent further damage to soft tissues and blood supply to the humeral head, but its success depends on satisfactory closed reduction, sufficient bone strength, minimal fragmentation, and good patient compliance. Intramedullary nail technique has good clinical efficacy and can provide more stable internal fixation, but discontinuous lateral cortical fragmentation is one of its major contraindications. Plate screw internal fixation is now one of the most commonly used surgical treatment methods for PHFs in clinical practice, with both traditional and locking plates available for selection. Locking plate internal fixation offers good angular stability and axial support and has gradually become the mainstream surgical treatment method for PHFs in recent years. Precise reduction of fracture fragments can be achieved through open reduction and internal fixation. However, the biomechanical stability of this technique significantly depends on sufficient bone mass support at the proximal end. For elderly patients with severe bone mass deficiency and poor blood supply at the fracture end, the locking plate internal fixation is very likely to fail, and the incidence of surgical complications has remained high. The main reasons for the failure of PHFs internal fixation include loosening of internal fixators, nonunion of fractures, necrosis of the humeral head, and secondary shoulder joint dysfunction. The management strategies for failed PHFs internal fixation and the selection of revision surgery plans have become important challenges in the current field of orthopedic and joint surgery. Reverse total shoulder arthroplasty (RTSA) has gradually become a treatment for cuff tear arthropathy since Grammont completed the biomechanical improvement. Effective methods for shoulder joint diseases, such as CTA and end-stage shoulder osteoarthritis, are still being developed, and current clinical research on the application of RTSA in revision after PHF internal fixation failure remains limited. Most existing studies are limited to small-sample, single-center retrospective analyses and lack support from high-quality multicenter randomized controlled trials (RCTs). In addition, the incidence and risk factors for complications after RTSA revision surgery remain unclear.

To explore the efficacy of reverse shoulder joint replacement surgery as a revision procedure in the treatment of failed internal fixation of proximal humeral fractures.

A retrospective analysis was conducted on 9 patients with failed plate internal fixation of proximal humeral fractures who were admitted from April 2018 to November 2023, including 2 males and 7 females. Age: 51 to 76 years old. All 9 cases underwent reverse shoulder joint replacement and revision surgery. Preoperative and postoperative systematic assessment of pain visual analogue scale (VAS), American shoulder and elbow surgeons' form (ASES) score, Constant-Murley shoulder score scale, University of California at Los Angeles UCLA score, disabilities of the arm, shoulder, and hand (DASH), shoulder pain and disability index Key indicators such as SPADI and joint range of motion were analyzed, and surgical complications were also analyzed.

All 9 cases were followed up. At the last follow-up, compared with that before the operation, the Angle of flexion and elevation increased from (53.89±19.65) ° to (107.78±25.26) °. The external rotation Angle increased from (3.33±9.68) ° to (31.67±6.61) °. The internal rotation Angle increased from (25.00±13.23) ° to (57.22±9.05) °. The abduction Angle increased from (48.33±16.95) ° to (95.00±15.00) °. The UCLA score increased from (9.33±3.60) points to (22.78±6.39) points. The Constant-Murley shoulder joint score increased from (23.44±5.70) points to (61.56±18.75) points. The ASES score increased from (34.11±9.66) points to (74.44±18.80) points. The DASH score decreased from (65.55±9.13) points to (31.73±11.05) points. The SPADI score decreased from (57.34±14.05) points to (23.77±16.35) points. The VAS score decreased from (5.00±1.73) points to (1.11±2.26) points. Furthermore, the differences in each score were statistically significant (P < 0.05). One case presented with aggravated postoperative pain. One case had a humeral shaft fracture during the operation.

Reverse shoulder joint replacement, as a revision for failed internal fixation of proximal humeral fractures, has reliable efficacy and good clinical application value.