Fig. 10.1
Proximal humerus nonunion with varus collapse noted after open reduction and internal fixation with screw penetrance into glenohumeral joint. Laboratory workup was equivalent and decision for two-stage procedure was made. Multiple cultures grew P. acnes
Specific Proximal Humerus Nonunions
Tuberosity Nonunion
The literature on the management of tuberosity nonunions is small as the majority of tuberosity fractures heal, but often in a malunited position. However, when tuberosity nonunion does occur, pain and disability can be substantial. The primary difficulty in repairing tuberosity nonunions is the size and quality of the bony fragment that is remaining.
Greater tuberosity nonunions can lead to significant weakness, impingement, or both. The majority of the rotator cuff attaches to the greater tuberosity so a nonunion will render the rotator cuff incompetent and lead to a clinical situation that is similar to a large/massive rotator cuff tear [17]. The fragment is often displaced in a superior and posterior direction secondary to the pull of the rotator cuff. This superior displacement can lead to abutment with the overlying acromion and secondary impingement and pain.
Lesser tuberosity nonunions can also lead to significant pain and disability. The lesser tuberosity is the insertion site for the subscapularis and a nonunion can produce subscapularis insufficiency. The patient will often present with anterior shoulder pain and internal rotation weakness. The physical exam is similar to a subscapularis tear exam producing a positive belly press test and inability to do a lift-off test.
Repair of greater and lesser tuberosity nonunions can be surgically approached differently secondary to their respected location but the underlying principles remain the same. Greater tuberosity nonunions are approached from a lateral based deltoid splitting incision and lesser tuberosity nonunions are typically managed through a deltopectoral incision. The surgeon must be very careful in not causing any further damage to surrounding soft tissues that could lead to further devitalization of the fragment. If the nonunion is chronic the attached rotator cuff will often be scarred to adjacent tissue and must be released to allow adequate mobilization of the fragment and repair of the rotator cuff if required. The bone of the proximal humerus needs to be debrided to bleeding tissue to allow for healing of the tuberosity. If the fragment is of sufficient size and adequately mobilized, then either cannulated or non-cannulated screws with washers in a compression technique may be utilized. Care must be taken when performing the final tightening of the screws as the tuberosity fragment can be split or fragmented during fixation. If only one screw is possible then the repair can be augmented with suture fixation to surrounding rotator cuff or bony tunnels can be created in the proximal humerus for suture fixation. If the tuberosity fragment is of insufficient size to accept screw fixation an alternative is to excise the bony fragment and repair the rotator cuff to the proximal humerus using suture anchors or transosseous tunnels. The goal is to restore the rotator cuff to a bleeding bony bed for healing and restoration of rotator cuff function.
Surgical Neck Nonunion
Surgical neck nonunions are the most common nonunions of the proximal humerus and often accompanied by tuberosity malunion, avascular necrosis of the humeral head, and posttraumatic glenohumeral osteoarthritis increasing the difficulty of treatment [11, 12, 18–20] (Fig. 10.2). Treatment of surgical neck nonunions can be difficult secondary to poor bone quality, distorted or disrupted anatomy especially in cases with prior surgical treatment, extensive soft tissue scarring, and cavitation of the humeral head. Most patients present with pain and loss of function. Treatment options must include stabilizing the nonunion to allow boney healing by the use of intramedullary devices, plating systems, or arthroplasty.
Fig. 10.2
Painful surgical neck nonunion in an 84-year-old female with cavitation of the humeral head and bone loss proximally
Intramedullary devices have been and continue to be used to treat surgical neck nonunions. The initial reports showed favorable results in achieving union. Neer reported results using an intramedullary device and tension band construct with bone grafting and noted union in 12 of 13 patients [12]. Nayak et al. and Norris et al. used a similar technique and noted very favorable results with union rates of 80 % [21, 22]. However, the initial success was complicated by the mechanical impingement from these devices and secondary rotator cuff dysfunction. This led to the need for secondary surgical procedures to remove hardware and perform soft tissue releases in an attempt to restore function. Revision procedures have been noted to be as high as 80 %. This high revision rate has led many surgeons to discontinue the use of these early intramedullary devices in the treatment of proximal humerus nonunions. Newer intramedullary devices have been designed to minimize secondary surgical procedures and rotator cuff dysfunction. Yamane et al. followed 14 consecutive patients treated with interlocking intramedullary nailing and bone grafting for proximal humerus nonunion and noted 100 % union rate and improvement in clinical outcomes [23]. Overall, history has not favored the use of intramedullary nails and other fixation devices may provide better stability to promote bone healing.
Plate Fixation
Successful surgical treatment of proximal humerus nonunions has been well documented using plate fixation. Adequate bone stock to place the hardware, a viable humeral head, and the absence of glenohumeral arthritis are required. T plates were originally utilized with some difficulty in obtaining adequate stability in the remaining bone. This prompted the use of blade plates which required less bone for fixation proximally and the plate acting as a tension band construct that counteracts the force of the rotator cuff reducing the forces on the repair and helped to promote bony union. Recently, the use of locking plates has been recommended in bone of poor quality to give added stability to promote healing.
Galatz et al. evaluated 13 patients with surgical neck nonunions treated with either a T plate or blade plate with autogenous bone grafting and reported union in 12 of 13 patients with excellent clinical results 11 of 13 patients. Patients with avascular necrosis, arthritis, humeral head bone loss, or nonunion of the tuberosities were excluded from the study [24]. Allende prospectively evaluated seven patients with documented atrophic nonunions of the proximal humerus treated with a blade plate and reported union in all seven patients [25]. Tauber et al. treated 45 patients with established surgical neck nonunions with blade plate fixation with no bone grafting and reported union in greater than 90 % of patients [26]. Ring et al. used blade plate and autogenous bone graft in 25 patients with proximal humerus nonunion and reported union in 23 of 25 patients [27]. Badman et al. evaluated 18 patients with symptomatic proximal humerus nonunions and treated them using a fixed-angle locked plate and also bone grafted by using an intramedullary strut allograft and reported union in 94 % of patients [28].
Regardless of the treatment plan chosen the surgeon needs to provide a biologic environment conducive to bony union and provide mechanical stability to support healing while minimizing trauma to surrounding structures. The approach can either be a deltopectoral approach or a lateral approach depending on surgeon preference. The surgeon must be aware of the distortion of the anatomy which commonly occurs with proximal humeral nonunions. Caution should be exercised during dissection as to not injure the axillary or musculocutaneous nerves. We recommend finding the biceps tendon and corresponding intertuberculous sulcus, this will aid in identification of anatomy. The biceps should either be tenotomized or tenodesed depending on surgeon preference. All interposing tissue at the nonunion site should be removed and bleeding bone both proximally and distally needs to be achieved. Once the bone has been prepared and ready for fixation the use of K-wires or Steinman pins can be a useful aid to assist in controlling the bony fragments. No matter what type of fixation is chosen the surgeon should have orthogonal views to ensure adequate reduction and avoidance of malunion and to ensure that hardware has not penetrated the glenohumeral joint. We recommend the use of intraoperative C-arm in all cases. After appropriate reduction and fixation the nonunion site should be inspected for bone loss and recommend bone grafting of some nature in all cases. After fixation stability and range of motion of the shoulder joint should be tested and if there are contractures of the capsule or surrounding soft tissue a release may be performed. This will aid in rehabilitation postoperatively and limit force transmission to the nonunion site [11].
Prosthetic Replacement
There is little literature that specifically addresses arthroplasty as a treatment for proximal humeral nonunions. More commonly arthroplasty is discussed in the setting of reconstructive salvage procedures for proximal humerus fractures. However, arthroplasty may be the only option especially when the patient with a proximal humerus nonunion presenting with avascular necrosis of the humeral head, inadequate bone stock, articular defects, and posttraumatic osteoarthritis. Boileau et al. evaluated hemiarthroplasty in six surgical neck nonunions and all required an osteotomy of the greater or lesser tuberosity for anatomic positioning of the implant. All six patients were reported to have poor or fair results [29]. An additional study in 2006 evaluated 22 nonunions of the surgical neck treated with nonconstrained shoulder arthroplasty (hemiarthroplasty or total shoulder arthroplasty) and reported very poor results secondary to the need for greater tuberosity osteotomy and recommended that all attempts should be made to perform open reduction and internal fixation over nonconstrained shoulder arthroplasty in the management of proximal humerus nonunions [30]. Mansat et al. reported when dealing with late sequelae of proximal humerus fractures that performing a greater tuberosity osteotomy worsened the final results [31]. Duquin et al. performed hemiarthroplasty in 54 patients and total shoulder arthroplasty in 13 patients with a proximal humeral nonunion and noted inconsistent tuberosity healing with less than 50 % of patients having a satisfactory outcome at final follow-up [32]. Dines et al. so reported poor results and cautioned to avoid a tuberosity osteotomy during treatment of proximal humerus nonunions with arthroplasty [33]. Other studies have also evaluated hemiarthroplasty and total shoulder arthroplasty in proximal humerus nonunions and have noted that they appear to have poor results and higher complication rates when used in posttraumatic sequelae or if the nonunion was noted after a prior failed ORIF [34, 35]. Therefore, based on the literature our recommendations for hemiarthroplasty or total shoulder arthroplasty in the setting of a proximal humerus nonunion the surgeon should try to restore the normal anatomical alignment with the prosthesis while avoiding tuberosity osteotomy.
Another intriguing option in the management of proximal humerus nonunions is the reverse total shoulder arthroplasty. The reverse total shoulder arthroplasty does not depend on an intact rotator cuff to function properly and therefore is not as dependent on exact anatomic tuberosity positioning as hemiarthroplasty or total shoulder arthroplasty (Fig. 10.3). Martinez et al. specifically looked at treating proximal humerus nonunions with a reverse total shoulder in 18 patients [36]. Fourteen of 18 patients were satisfied with the result of surgery, but they did report 2 postoperative dislocations out of the 18 initially treated. Their conclusion was that the reverse total shoulder provided improved pain relief and motion, but with an apparent higher risk of dislocation [36]. Boileau et al. evaluated the Grammont reverse total shoulder for proximal humerus fracture sequelae in five patients and noted improved active elevation and Constant Scores, with no change in external rotation or internal rotation [37]. The reverse total shoulder may be a viable option in proximal humerus nonunions but should be considered only in older patients or younger patients who are physiologically older with low demands. The surgeon will have to be cautious in considering a reverse arthroplasty in a younger patient when no other viable option exists. The patient must fully understand the risks, benefits, and limited long-term clinic outcomes for the reverse total shoulder.
Fig. 10.3
Reverse total shoulder arthroplasty used to treat patient from Fig. 10.2. Patient noted significant pain relief postoperatively
Three- and Four-Part Proximal Humerus Nonunions
Three- and four-part proximal humerus nonunions are not very common because the tuberosities typically heal but are often in a malunited position. However, if a three- or four-part proximal humerus fracture does occur then the treatment recommendations are the same as outlined for surgical neck nonunions and isolated tuberosity nonunions. If adequate bone stock exists then open reduction and internal fixation with bone grafting would be the treatment of choice. If there is inadequate bone stock, avascular necrosis of the humeral head, or osteoarthritis, then hemiarthroplasty or total shoulder arthroplasty may be the best option. Hemiarthroplasty has been reported not to do as well in three- and four-part nonunions when compared to surgical neck nonunions [38]. In older patients with three- and four-part proximal humerus fractures we would recommend reverse total shoulder arthroplasty.
Conclusion
Proximal humerus nonunions are uncommon in comparison to the total number of proximal humerus fractures that occur. However, when encountered an appropriate preoperative evaluation must be undertaken in order to maximize treatment. Conservative treatment should be performed in patients who have minimal pain and minimal disability. Patients with significant pain and disability should undergo operative reconstruction. Currently no gold standard for treatment of proximal humerus nonunions exist. We recommend open reduction and internal fixation with bone grafting when possible and hemiarthroplasty or total shoulder arthroplasty for patients when there is inadequate bone stock, avascular necrosis of the humeral head, and underlying posttraumatic osteoarthritis. We recommend reverse total shoulder arthroplasty for elderly patients or those with very low physiologic demands.
Proximal Humerus Malunion
Proximal humerus malunions can be extremely difficult to manage even for experienced orthopedic shoulder surgeons. To adequately manage proximal humerus malunions the surgeon must understand the potential causes of malunion, appropriate preoperative evaluation, and available literature on the treatment of proximal humerus malunions.
A universally accepted classification system for proximal humerus malunions does not exist. The lack of a well defined classification system leads to difficulty when evaluating published patient outcomes and treatment recommendations. Several authors have created classification systems including Beredjiklian et al. who took into account both osseous and soft tissue abnormalities to make the surgeon aware that both are important in treatment and the final outcome [39]. Boileau et al. developed a posttraumatic sequelae classification system for proximal humerus fractures that included proximal humerus malunions, but this system relates to arthroplasty treatment [29] The most used classification is a descriptive classification that is a modification of Neer’s classification of acute proximal humerus fractures [40].
Fractures of the proximal humerus are relatively common and have been noted to represent 5–9 % of all fractures [21, 41, 42]. Proximal humerus malunions have been reported after both operative and nonoperative treatment of proximal humerus fractures. Proximal humerus malunion can lead to persistent pain, disability that affects the activities of daily living, and affect the quality of life of the patient.
Pathoetiology
The etiology of proximal humerus malunions is not complicated. Malunions arise from non-anatomic healing of the tuberosities, surgical or anatomical neck, or a combination. Malunions have been noted after both nonoperative and operative intervention. Lyengar et al. performed a systematic review of outcomes after nonoperative treatment of proximal humerus fractures and noted that varus malunion was the most common complication of nonoperative treatment [4]. The soft tissue attachments to the proximal humerus including the rotator cuff, pectoralis major, and deltoid account for the displacement of the fragments after acute fracture. The reason for proximal humerus malunion with nonoperative treatment is likely multifactorial including failure of the surgeon to recognize displacement of fracture fragments on initial films, inadequate follow-up of the fracture, patients to unhealthy to undergo surgery and early aggressive postoperative rehabilitation are a few possible reasons. Malunions have been documented to occur between 0 and 22 % after percutaneous pinning, open reduction and internal fixation, intramedullary nailing, and hemiarthroplasty in the treatment of proximal humerus fractures [5, 9, 23, 43, 44]. The causes of malunion after operative intervention include loss of fixation or inadequate initial reduction.
Treatment
Nonoperative Treatment
Nonoperative treatment has a role in malunions of the proximal humerus especially in patients with multiple medical comorbidities and those with very low functional demand. Not all proximal humerus malunions are painful enough or limit activities enough to prompt the patient to undergo surgery and for those patients we would recommend continued nonoperative treatment. However, patients who have a painful malunion with limited function we recommend operative management.
Operative Treatment
Tuberosity Malunion
Greater tuberosity malunion is the most common malunion of the proximal humerus (Fig. 10.4). The difficulty in treatment is related to the size of the remaining tuberosity, amount of displacement and any underlying soft tissue contractures. Greater tuberosity malunions are typically displaced in a superior and posterior direction secondary to the pull of the attached rotator cuff. The superior malposition can lead to contact of the greater tuberosity with the overlying acromion and can limit both abduction and forward flexion. The posterior displacement can lead to contact with the posterior glenoid and can lead to loss of external rotation. Significant weakness can be associated with greater tuberosity malunion related to rotator cuff dysfunction as seen in a massive rotator cuff tear [17].
Fig. 10.4
Thirty-year-old patient who had anterior glenohumeral joint dislocation and was treated nonoperatively for his greater tuberosity fracture. Note the posterior/superior malunited position of the greater tuberosity
Lesser tuberosity malunions are not seen as commonly as greater tuberosity malunions, but can lead to significant pain and disability when present. The pull of the subscapularis typically causes the lesser tuberosity to be pulled into a medial malunited position. This displacement can lead to both a decrease in internal and external rotation secondary to insufficiency and contracture of the subscapularis and impingement on the coracoid process. The patient will often complain of anterior shoulder pain and will have an exam that is consistent with a full thickness subscapularis tear.
The decision to operate on an isolated tuberosity malunion is continued pain and disability. Biomechanical studies have shown that minimal displacement of the greater tuberosity can lead to significant alterations in the motion of the glenohumeral joint [45]. Neer’s original description considered 1 cm to be amount of displacement that warranted surgery. Recent recommendation suggest as little as 5 mm of displacement of the greater tuberosity may causes pain and disability [40].
Open treatment of either greater or lesser tuberosity malunion is similar. The approach used can either be a lateral based approach or a deltopectoral approach. The surgeon should be prepared for distorted anatomy that will be encountered during the approach and great care should be taken to protect both the axillary and musculocutaneous nerves. The bicipital groove can be a readily identifiable landmark that can assist in dissection. An adequate subacromial and subdeltoid release should be performed to remove all adhesions. Often the identification of the tuberosity fragment can be difficult to define and we would recommend fluoroscopic assistance if there is any question about the position. Once the fragment is identified an osteotomy is performed using fluoroscopy to determine position of osteotome and tuberosity fragment. Extensive rotator cuff releases both subacromial and within the glenohumeral joint should be performed. A release of the rotator interval and capsular release both anterior and posterior to assist in mobilization of fragment and glenohumeral joint is usually needed. Traction sutures can be placed in the rotator cuff attached to the tuberosity and to assist the surgeon when performing the soft tissue releases. If an internal rotation contracture is noted then we suggest anterior, posterior, and superior release of the subscapularis. After osteotomy and preparation of soft tissues are complete the bony bed for repair must be prepared by removing all scarred and devitalized tissue down to a healthy bleeding bony bed. The tuberosity fragment should be able to be placed in the anatomic site for repair. If this is not possible then the tuberosity should be advanced as close as possible and kept below the humeral head. Fluoroscopy can be used to assist in tuberosity reduction if the anatomy is distorted. If the fragment is large enough we recommend fixation with compression screw and washer construct. This may be backed up with nonabsorbable suture because hardware loosening has been reported [46]. If the fragment is of insufficient size for screw fixation then we recommend suture fixation using either anchors or transosseous tunnels with multiple passes through the rotator cuff and proximal humerus. After repair the arm should be taken through a range of motion to identify quality of repair and to set limits on postoperative rehabilitation. Early passive and active assisted range of motion is encouraged if repair is sufficient. No resistive strengthening therapy should be instigated until bony fragment or soft tissue has incorporated.
Related posts:
Hemiarthroplasty for the Treatment of Proximal Humerus Fractures
Nonoperative Treatment of Proximal Humerus Fractures
Reverse Shoulder Arthroplasty for Proximal Humerus Fractures
Closed Reduction and Percutaneous Fixation of Proximal Humerus Fractures
Intramedullary Locking Nail Fixation of Proximal Humerus Fractures: Rationale and Technique
Anatomy and Classification of Proximal Humerus Fractures
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