Preoperative evaluation
1. Three factors should be considered in the process of deciding on the best treatment for any particular proximal humeral fracture. These three factors are the physiologic status of the patient, the experience level of the surgeon, and the severity of the fracture. The incidence of proximal humeral fractures is as high as 105 per 100,000 people. Epidemiological studies reveal a unipolar age distribution, with the highest age-specific incidence in women aged 80-89 years, and many patients with proximal humeral fractures are elderly and have limited expectations.
Therefore, surgical treatment is rarely indicated for fractures occurring in patients of advanced age and those with cognitive deficits or severe medical co-morbidities. The most common medical problems that cause very poor outcomes or increase the risk of complications are severe osteoporosis, heavy tobacco, drug or alcohol use, diabetes, rheumatoid arthritis, steroid medication, and concurrent malignancies.
2. Imaging evaluation, most traditionally, remains standard radiographic plain films, including anteroposterior, lateral, and axillary views of the scapula. MRI can provide a more reliable interpretation of the soft tissues surrounding the shoulder joint, and if necessary, angiography is also feasible to clarify the blood supply to the humeral head.
3. The most commonly used clinical staging of fractures is still the staging theory proposed by Neer in 1970. It divides the proximal humerus into four parts, namely the humeral head, the greater and lesser tuberosities, and the humeral stem. However, the Neer classification still has many limitations: most stable and embedded fractures, regardless of the number of fracture components, can be treated nonoperatively, whereas certain fracture types have a better prognosis after reduction and fixation but are not described by the Neer classification.
More subtle differences in fracture displacement, assessment of humeral head viability, and involvement of the articular surface may have a greater impact on outcome, yet are not well classified in the Neer system.
Treatment of fractures
1. Indications for surgery: Most fractures have stable structures and heal functionally with nonoperative treatment. Indications for non-operative treatment are that all five of the following criteria are met.
1) The humeral head is in position;
2) contact or insertion between the head and stem;
3) minimum internal or external rotation of the humeral head into an angle (head-stem angle between 100° and 160°);
4) Involvement of the minimal articular surface;
5) minimal displacement of any nodal fracture from the head. Most of the fractures met these criteria and restored satisfactory functional outcome with nonoperative treatment.
The remaining patients were considered for surgical treatment. In these patients, the type of surgical intervention is mostly based on the patient’s age, local and systemic conditions, fracture typing, stability, bone quality, whether other organ injuries are combined, and the patient’s expectations of postoperative function.
The aim of surgical treatment is to achieve anatomical repositioning and stable fixation, but anatomical repositioning in the strict sense is almost impossible.
3.Surgical methods.
3.1 Closed reduction percutaneous internal fixation. It is very effective for two-part surgical neck fractures and even some three- or four-part fractures with good bone condition. Detailed knowledge of the anatomy of the axillary and musculocutaneous nerves can avoid surgical injury. In osteoporotic patients, it is most important to make the end threads of the bone round pin occlude the subchondral bone of the humeral head; however, this also increases the risk of the bone round pin entering the joint. Intraoperative fluoroscopy with multiple angles can avoid this complication.
A range of passive motion of the joint is initiated immediately after surgery. Percutaneous needle penetration minimizes surgical damage to soft tissues, which preserves more of the biology of the fracture site compared to other techniques. A retrospective study of 83 patients compared incisional reduction with percutaneous needle fixation. The two groups were comparable in age and fracture type. 12 patients were treated with incisional internal fixation and 71 patients were treated with percutaneous needle penetration.
The results of the study showed that the incisional reduction had a higher rate of osteonecrosis compared to the percutaneous needle penetration method due to secondary injury from the procedure. The main complications of this procedure are pin tract infection, re-displacement of the fracture fragment, and pin displacement. This approach is best suited for patients with good bone quality who are able to follow active postoperative activity instructions. This technique is not suitable for anatomic neck fractures, comminuted humeral head fractures, and insertion fractures with severe valgus angulation.
Fenichel et al. retrospectively studied 50 patients with unstable two- and three-part fractures using this technique without nail tract infection, osteonecrosis, or neurovascular complications, but seven patients had fracture re-displacement, and three of them underwent reoperation. They recommended careful patient selection as well as close follow-up for 4 weeks postoperatively to reduce such complications.
3.2 Intramedullary nail fixation. The advantage is that the blood supply around the fracture is protected by indirect reduction. This technique is more often used in patients with two-part surgical neck fractures, especially in patients with concomitant humeral stem fractures, and rarely in patients with major and minor tuberosity fractures. The disadvantages are mainly potential rotator cuff injury and chronic shoulder pain.The Polarus nail is a commonly used intramedullary nail in the treatment of proximal humeral fractures.
Kazakos et al] on 27 cases of proximal humerus fractures treated with the Polarus nail found that none of the cases had osseous nonunion, one case had frozen shoulder, and one case had ischemic humeral head necrosis. the Constant score was excellent in 6 cases, satisfactory in 15 cases, unsatisfactory in 4 cases, and poor in 2 cases, with an excellent rate of 77.78%. Clinical outcomes did not correlate well with Neer’s staging, with a significant improvement in young and middle-aged people under 65 years of age compared with older people over 65 years of age.
The AO proximal humeral intramedullary nailing system with a spiral blade is also a more common fixation device in the clinic, with a spiral blade at the proximal end that helps anchor the humeral head, especially in osteoporotic patients. Large displaced tuberosity fractures and four-part fractures are not suitable for this type of internal fixation.
3.3 Incisional reduction plate screw internal fixation. In the case of proximal humerus fractures, anatomic repositioning is essential for the restoration of joint function because it directly affects the function of the shoulder joint. At the same time, the process of fracture healing should minimize bleeding and scab formation, reduce the pressure on the periosteal tissue, and protect the blood supply to the epiphysis as much as possible.
The latest development of steel plate technology, i.e., locking plate technology, is now widely used in clinical practice. Its core improvement is that the screw is locked by the thread between the screw and the plate, and the LCP (PHILOS) of the proximal humerus can provide higher stability compared with the common LC-DCP, and the angle stabilization technology between the screws can provide stronger fracture block for comminuted fractures of the proximal humerus, especially in osteoporotic patients. The plate itself also provides a stronger grip on the rotator cuff. The plate itself also provides a force point for rotator cuff repair.
3.4 Bone suturing. In elderly and osteoporotic patients with low expectations for postoperative functional recovery, sutures provide a suitable stabilizing structure to achieve functional fracture repositioning. In proximal humeral fractures with inversion deformity, according to the tension band principle, it is necessary to fix the small and large tuberosities by tying them to the humeral head below the plane of the humerus and fixing them in the distal humeral cortical bone by downward retraction or with the distal end by riveting.
For the repair of the rotator cuff is also an integral part of the femoral suture. It can enhance the stability of the postoperative shoulder joint in osteoporotic patients, but the occurrence of postoperative tissue adhesions and soft tissue exfoliation is detrimental to the recovery of shoulder function and can lead to failure of the procedure.
3.5 Arthroplasty. Arthroplasty is recommended for elderly patients with Neer4 fractures of the proximal humerus involving the articular surface, severe destruction of the blood supply to the humeral head, and possible postoperative humeral head necrosis. In elderly patients with generally well-displaced three- and four-part fractures, there is controversy as to whether to adopt incisional internal fixation or to perform hemiarthroplasty. Displaced four-part fractures are associated with a 21% to 75% rate of osteonecrosis, whereas this figure is only 8% to 26% in patients with insertional exostosis four-part fractures. This argument favors hemiarthroplasty in older patients with displaced comminuted proximal humeral fractures.
Gadea F et al. reported 138 cases in which a hemiarthroplasty was used and found an excellent rate of 88.13% for the prosthesis decade, 100% for the RA (rheumatoid arthritis) group, 94.13% for the AN (avascular necrosis) group, and 94.13% for the PO (primary osteoarthritis) group. (primary osteoarthritis) group 81.5%, Cuff tear group 76.8% Constant-Murley score, RA group 55.3, AN group 60.7, PO group 57.7, Cuff tear group 46.2.
It was found that hemiarthroplasty was more effective than RA and rotator cuff injury for simple osteonecrosis. In recent years, reverse shoulder arthroplasty has been recognized in clinical applications and is better than hemiarthroplasty for postoperative shoulder function, especially for rotational function. In a comparative study of 11 reverse shoulder replacements versus 12 hemi shoulder replacements, it was found that postoperative anterior flexion and ASES scores were better in patients with reverse shoulder replacements than in hemi shoulder replacements.
A study completed in 2011 showed that postoperative pain, functional scores, and revision rates at 20 years of follow-up were significantly different in patients with shoulder arthroplasty combined with rotator cuff injury and shoulder osteoarthritis or rheumatoid arthritis than in the control group.
4. Complications
Including stiffness of the shoulder joint, others include resting pain, postoperative infection, ischemic necrosis of the humeral head, failure of internal fixation, non-union of the fracture, and distant development of rotator cuff injury. Postoperative stiffness is the most common complication, which is caused by postoperative pain and adhesions in the tissues after prolonged braking. Therefore, intraoperative immobilization, appropriate postoperative bouts of pain, and encouragement of early functional exercise have positive significance in preventing soft tissue adhesions. If rehabilitation is not effective arthroscopic, capsular release, subacromial decompression and removal of any impingement producing metal can be performed.
Summary
The treatment of proximal humeral fractures is evolving with the understanding of fracture classification and innovations in surgical techniques and instrumentation. Orthopaedic surgeons should individualize the treatment plan for patients with proximal humerus based on the patient’s condition and fracture type. Treatment decisions should include assessing the vascularity of the humeral head, determining the best fixation, and taking local adjuncts to promote anatomic healing of the fracture and prevent postoperative complications. In light of the recent continuous development of locking plate technology and the maturation of shoulder prostheses, the clinical effectiveness of the new techniques is gradually being recognized by the industry, and the surgical treatment of proximal humeral fractures will be taken to a higher level.