Distal Humerus Fractures in Maintenance Hemodialysis Patients with Forearm Arteriovenous Shunts: Two Case Reports

Introduction

Patients with chronic renal failure and those undergoing long-term dialysis often develop fibrous osteitis due to secondary hyperparathyroidism, resulting in high bone turnover, as well as osteomalacia and osteopenia, which are associated with low bone turnover [1–3]. Furthermore, bone destruction and dialysis-related amyloidosis–induced cyst formation cause structural deterioration and increased bone fragility [4]. Consequently, fragility fractures occur more frequently in patients with chronic renal failure or long-term dialysis [5,6].

Distal humerus fractures in the presence of bone fragility are difficult to stabilize, and nonoperative treatment carries a high risk of pseudarthrosis [7]. Therefore, rigid fixation is required to ensure bone healing [8]. The posterior approach is commonly used for plate fixation of distal humerus fractures [9]. However, when fractures occur in limbs containing a dialysis shunt, this approach poses a risk of injury to a shunt located on the anterior forearm due to physical pressure exerted during surgery. Although limited evidence exists, studies of distal radius fractures with ipsilateral arteriovenous shunts have emphasized the importance of preserving shunt function during surgery and shown that appropriate surgical strategies can produce favorable outcomes [10,11]. Similar precautions are necessary for distal humerus fractures with ipsilateral shunts.

We encountered 2 patients with chronic renal failure who sustained distal humerus fractures in their dialysis shunt-bearing limbs. Both fractures achieved complete bone union and no postoperative shunt complications after plate fixation via medial and lateral skin incisions in the supine position without tourniquet use. This report aims to describe the surgical management and outcomes of distal humerus fractures in hemodialysis patients with ipsilateral arteriovenous shunts; it emphasizes preserving shunt function while achieving stable fixation.

Case Reports

CASE 1:

A 62-year-old man with chronic renal failure sustained a distal humerus fracture in his non-dominant limb, which contained a previously occluded dialysis shunt. The fracture was classified as AO type C1 (Figure 1A, 1B). Surgery was performed as described in the “Surgical Technique” section below.

Postoperatively, the limb was immobilized in a splint for 1 week, followed by gradual elbow mobilization. At final follow-up, elbow motion was 120° flexion, 0° extension, 90° pronation, and 90° supination. Grip strength was 77.3% of the contralateral side. The visual analog scale (VAS), Quick Disabilities of the Arm, Shoulder, and Hand (Q-DASH), and Mayo Elbow Performance Score (MEPS) were 0, 0, and 100, respectively. Radiographs confirmed bone union (Figure 1C, 1D). No shunt dysfunction, soft tissue complications, or implant-related issues were observed.

CASE 2:

A 64-year-old woman with chronic renal failure sustained a distal humerus fracture in her dominant limb containing a functioning dialysis shunt. A new shunt had been placed in this limb because the previous shunt in the non-dominant limb had become occluded (Figure 2A). The fracture was classified as AO type A2 (Figure 2B, 2C). Surgery was performed as described in the “Surgical Technique” section below.

Postoperatively, the limb was immobilized in a splint for 1 week, followed by elbow mobilization. At final follow-up, elbow motion was 135° flexion, −5° extension, 85° pronation, and 85° supination. Grip strength was 100% of the contralateral side. The VAS, Q-DASH, and MEPS were 1, 9.09, and 85, respectively. Radiographs confirmed bone union (Figure 2D, 2E). No complications related to the shunt, soft tissue, or implant were observed, and plate removal was not required.

SURGICAL TECHNIQUE:

Surgery was performed under general anesthesia and brachial plexus block without the use of an air tourniquet. Open reduction of the distal humerus was followed by internal fixation with medial and lateral locking plates (VA-Distal Humerus Plates, DePuy Synthes, Tokyo, Japan) (Figure 3A, 3B). In Case 1 (type C1), the articular surface was first reduced and temporarily fixed with Kirschner wires, effectively converting the fracture to type A; this was followed by medial and lateral plate fixation. In Case 2 (type A2), temporary fixation with Kirschner wires preceded plate osteosynthesis. Intraoperative shunt patency was confirmed by palpation of the pulse and thrill. Postoperatively, patency was confirmed by auscultation for a continuous bruit. A previous report noted increased vascular diameter and blood flow rate on the shunt side relative to the non-shunt side [12]. Hemostasis was meticulously achieved by electrocautery at 15 kHz; no topical hemostatic agents were applied. Postoperative care included 1 week of splint immobilization, followed by gradual elbow mobilization.

OVERALL OUTCOMES:

The mean postoperative follow-up period was 13 (range: 12, 14) months. Mean elbow ranges of motion were 127.5° flexion, −2.5° extension, 87.5° pronation, and 87.5° supination. Mean grip strength was 88.7% of the contralateral side. Mean VAS, Q-DASH, and MEPS were 0.5, 4.5, and 92.5, respectively (excellent in 1 patient and good in 1 patient) (Table 1). Radiographs confirmed bone union in both cases. No transient shunt dysfunction, soft tissue complications, or implant-related issues occurred during rehabilitation; plate removal was not required (Figure 4).

Discussion

This case report demonstrates that distal humerus fractures in hemodialysis patients can be successfully managed with locking plate fixation while preserving the ipsilateral arteriovenous shunt. The key finding from these cases is the importance of meticulous surgical planning to achieve stable fixation while minimizing the risk of shunt injury.

Several treatment approaches have been reported for distal humerus fractures. Non-operative management may be considered for patients with nondisplaced fractures or comorbidities that contraindicate surgery; however, it often results in pseudarthrosis or a painful, stiff elbow [7,13,14]. Surgical techniques include the use of Kirschner wires (K-wires), screws, or locking plates [13,15,16]. Although locking plate fixation may be associated with postoperative contracture or symptomatic heterotopic ossification, it provides superior functional outcomes relative to osteosynthesis using K-wires or screws alone, with reported union rates exceeding 90% [13,16–18]. Therefore, locking plate fixation is recommended to enable early mobilization and promote bone union. Even in typical cases of distal humeral fractures, locking plate fixation remains the preferred approach. In patients with chronic renal failure, whose compromised bone quality predisposes them to fragility fractures [5,6], fixation methods other than locking plates may not achieve sufficient stability for union. Accordingly, osteosynthesis using locking plates was selected during both cases in the present report.

For hemodialysis, vascular access is typically created by anastomosing the radial artery and cephalic vein in the forearm to form an internal shunt [19,20]. Patients undergoing dialysis often exhibit hemostatic abnormalities [21]. Moreover, the vascular diameter and blood flow rate are greater on the shunt side than on the contralateral side [12]. Consequently, active surgical intervention for fractures on the shunt side is often avoided due to concerns about intraoperative bleeding. However, non-surgical treatment, such as cast immobilization for fractures on the shunt side, precludes puncture and auscultation of the dialysis shunt [10].

In contrast, safe access to the distal humerus can be achieved through a combined medial and lateral approach. In the present cases, despite the absence of tourniquet use, meticulous coagulation and hemostasis with electrocautery allowed open reduction and internal fixation without difficulty in achieving hemostasis. Furthermore, by minimizing pressure on the anterior forearm through supine positioning, mechanical stress on the shunt was reduced during surgery, potentially decreasing the risk of shunt occlusion. A previous study indicated that in dialysis patients with distal radius fractures on the shunt side, surgical treatment produced functional and radiographic outcomes superior to those of cast immobilization [11]. Although shunt preservation may increase operative time, the maintenance of shunt patency for postoperative dialysis function justifies this approach. These trade-offs should be carefully considered when determining surgical strategy. In the present cases, surgical management to minimize mechanical stress on the shunt, rather than cast immobilization, likely resulted in improved functional and radiographic outcomes. From the perspective of shunt preservation, it may be advisable to avoid posterior approaches, such as total elbow arthroplasty or distal humeral hemiarthroplasty.

In the present report, plates were applied using a combined medial and lateral approach. In Case 1, a type C fracture was converted to a type A fracture through reduction and provisional fixation of the intra-articular component using the same approach. In type A fractures, osteosynthesis with medial and lateral plates can be performed after provisional fixation. However, in type C3 fractures, reduction of the articular surface is difficult with a combined medial and lateral approach; osteosynthesis must be performed through a posterior approach [22]. We note that a posterior approach carries a risk of injuring a dialysis shunt on the anterior forearm because of physical pressure applied to that area. Our surgical approach for locking plate fixation in distal humerus fractures among dialysis patients was determined according to the flowchart (Figure 5). The findings suggest that when managing distal humerus fractures on the shunt side in dialysis patients, if the goals are to protect the shunt and achieve anatomic reduction and fixation, locking plate fixation through a combined medial and lateral approach in the supine position is an effective technique. In these 2 cases, the outcomes of locking plate fixation for distal humerus fractures were comparable to those previously documented in patients without chronic renal failure or long-term dialysis [9]. The proposed approach allows optimal fracture management while preserving the dialysis shunt.

Conclusions

Locking plate fixation of distal humerus fractures in hemodialysis patients with ipsilateral arteriovenous shunts, performed through combined medial and lateral approaches in the supine position without tourniquet use, achieved stable fixation, complete bone union, and preserved shunt function in both cases. This method appears to be a safe and effective option for managing such fractures while minimizing the risk of shunt-related complications and ensuring satisfactory functional recovery.