Half-wedge osteotomy and reverse repositioning for dorsal malunion distal radius fracture: a preliminary report with a case series

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Arch Hand Microsurg. 2025;30(1):29-35

Publication date (electronic) : 2025 February 12

doi : https://doi.org/10.12790/ahm.24.0053

Sangwoo Kim^,1, Hyunsik Park¹, Jongick Whang²

¹Department of Orthopedic Surgery, Institute of Hand and Microsurgery, Duson Hospital, Ansan, Korea

²Department of Plastic and Reconstruction Surgery, Institute of Hand and Microsurgery, Duson Hospital, Ansan, Korea

Corresponding author: Sangwoo Kim Department of Orthopedic Surgery, Institute of Hand and Microsurgery, Duson Hospital, 114 Seonbugwangjang 1-ro, Danwon-gu, Ansan 15368, Korea Tel: +82-31-402-0114 Fax: +82-31-414-1903 E-mail: kh658@hanmail.net

Received 2024 October 20; Revised 2024 November 13; Accepted 2024 November 16.

Abstract

Introduction

Malunion is a prevalent complication of distal radius fractures. Distal radius malunion may alter the normal kinematics of the wrist, leading to carpal malalignment and ulnocarpal impaction [1]. Therefore, distal radius malunion may cause wrist pain, decreased range of motion, midcarpal instability, or any combination of these complications. The main causes of malunion include re-displacement after closed reduction of the distal radius fracture and lack of timely treatment of distal radius fractures at the early stage [2]. Notably, in most cases, considering the mechanism of injury, there is increased dorsal tilt, which results in carpal subluxation, painful deformities, and loss of flexion and pronation [3].

In cases of extraarticular dorsal angulation malunion, if the dorsal angulation exceeds 30°, stiffness and restricted pronation-supination of the forearm may occur, necessitating surgical intervention [4]. Surgical treatment typically involves radial osteotomy, ulnar shortening, or bone grafting. In 1988, Fernandez [5] introduced a dorsal approach for corrective osteotomy. Classically, bony malpositioning has been approached from the dorsal side as an opening-wedge osteotomy, with a structural bone graft and plate osteosynthesis used to maintain alignment. The dorsal approach is used between the second and fourth extensor compartments. This approach has the advantage of technical ease when performing an opening-wedge osteotomy and the mechanical advantage of fixation on the tension side of the dorsal malunion distal radius fracture. Historically, extensor tendon irritation or rupture has been considered a drawback to dorsal plating. Therefore, the introduction of fixed-angle volar plates makes the volar approach viable for dorsally angulated malunion distal radius fracture [5,6]. This approach significantly reduces complications associated with extensor tendon irritation.

There are two methods for correcting malunion through the volar approach: open-wedge corrective and closed-wedge osteotomies. Open-wedge osteotomy is a common technique for dorsal malunion of distal radius fractures. However, it requires a bone graft, achieving proper reduction can be challenging, and instability can occur at the osteotomy site before complete healing [7].

However, closing-wedge osteotomy of the distal radius provides direct bone-to-bone contact and a more stable structure, eliminating the need for a separate bone graft donor site. However, closing-wedge radial osteotomy usually requires ulnar shortening.

Therefore, in this study, we introduced a novel surgical technique for achieving a double correction effect in cases of extraarticular dorsal angulation and distal radius malunion. The procedure involved performing a closed radial wedge osteotomy at half of the correction angle, followed by a 180° rotation and repositioning of the cutting bone.

Methods

This study includes five cases of distal radius corrective and ulnar shortening osteotomies performed at our institution between 2017 and 2021. The average age of the patients was 62.4 years (range, 58–69 years), with three females and two males. The mean follow-up period was 17.6 months (range, 12–24 months). In all cases, malunion that occurred after a fracture was diagnosed at another institution, with displacement progressing during conservative treatment with a sugar-tung splint or short-arm cast. On average, patients presented to our institution 13.4 weeks (range, 10–16 weeks) after the injury, and a single orthopedic surgeon performed all surgeries. Indications for surgery were defined as follows: (1) dorsal angulation of ≥10°on plain radiograph, (2) >8 weeks after injury, and (3) inability to perform daily activities due to wrist pain.

Preoperative and postoperative volar tilt and ulnar variance were assessed using radiographic imaging, and the bone union was confirmed using computed tomography (CT) scans at 6 months postoperatively. The visual analog scale (VAS) and quick Disability of the Arm, Shoulder, and Hand (qDASH) scores were evaluated preoperatively and at the final outpatient follow-up to assess symptoms.

1. Surgical method

The basic concept is that half of the correction angle is rotated by 180° in both the anteroposterior (AP) and lateral planes; therefore, performing bone grafting again will result in a double correction angle. The advantage of this surgical method is that it reduces the extent of corrective osteotomy, minimizes radial shortening, and reduces the length of the ulnar shortening osteotomy.

Furthermore, to explain this more clearly through a diagram, the two orange triangles in Fig. 1 represent the target correction angles. As shown in Fig. 1, we can achieve double correction if we perform an osteotomy at only half of the angle (one orange triangle) and rotate it by 180° for insertion. Therefore, when applying this concept in actual surgical cases, because the distal radius is three-dimensional rather than two-dimensional, we need to rotate the radial and ulnar sides as well as the volar and dorsal sides to achieve the correct correction angle.

Fig. 1.

The two orange triangles represent the correction angle. The desired correction angle can be achieved if one triangle rotates at 180°. Asterisks indicate rotational wedge bones.

Brachial plexus anesthesia was administered with the patient in the supine position using the modified Henry approach. Preoperative CT and radiography were performed to determine the correction angle, aiming for a volar angulation of 10°. Corrective osteotomy was performed from the volar to the dorsal side using a saw at half of the planned correction angle. A Kirschner wire (K-wire) was inserted at the angle where the saw would enter, and the osteotomy angle was confirmed using a C-arm. A Hohmann retractor was used to protect the extensor tendons and avoid injury, and osteotomy was performed only up to half of the correction angle.

After osteotomy, the cut bone was rotated by 180°, switching the radial and ulnar positions on the AP plane and the volar and dorsal positions on the lateral plane before being reinserted into the osteotomy site. Temporary fixation was achieved using a K-wire, and final fixation was performed using a variable angle volar locking plate (DePuy Synthes, Warsaw, IN, USA). Furthermore, the volar angulation was adjusted to match the plate.

Subsequently, the ulna was shortened by the positive length, as confirmed using the C-arm. A lateral approach to the ulna was performed between the flexor and extensor carpi ulnaris muscles to proceed with ulnar shortening. The shortening length was determined based on the ulnar positive length measured in the preoperative power grip view and the positive length obtained intraoperatively after corrective osteotomy. An oblique osteotomy method was used, and fixation was achieved using a lag screw and a plate with screws (DePuy Synthes). The cancellous bone obtained from ulnar shortening was then used as a bone graft at the radius correction osteotomy site. Figs. 2A–2H show the step-by-step surgical procedure.

Fig. 2.

(A) Dorsal angulated malunion an anteroposterior (AP) radiograph showing severe positive ulnar variance. (B) Preoperative lateral radiograph showing dorsal tilt angulation. (C) Half osteotomy C-arm photograph. (D) Gross half-wedge bone gross photograph. (E) 180° reversed repositioning wedge bone. (F) Repositioning the wedge bone and plating. (G) Postoperative 6-month AP radiograph showing improved ulna variance. (H) Postoperative 6-month lateral radiograph showing improved distal radius dorsal tilt.

Postoperative rehabilitation allowed immediate movement of the distal, proximal, and metacarpophalangeal joints. A short-arm splint was applied for 6 weeks, and strengthening exercises or forceful gripping were restricted during this period. Wrist joint movement was permitted starting 6 weeks postoperatively.

Results

Five patients were included in the study. Bone union was achieved in all cases, and a CT scan performed 6 months postoperatively confirmed callus formation, indicating progressive bone healing. The average preoperative volar tilt improved from –42.8° (dorsal, 32°–50°) to 7.8° (3°–12°). The average length of ulnar shortening was 4 mm (range, 3–6 mm), and bone union was confirmed in all cases. The ulnar variance was 8.6 mm; however, it reduced to 2.4 mm postoperatively (Table 1).

Table 1.

Clinical data

The VAS score improved clinically from 7.6 to 0.4, and the qDASH score improved from 75.9 to 8.2 (Table 2). Fig. 3 shows the recovery of range of motion 6 months postoperatively.

Table 2.

Postoperative improvements

Fig. 3.

Wrist motion at a 6-month postoperative follow-up.

Discussion

There are no absolute surgical indications for malunion of distal radius fractures. Therefore, the degree of impairment and functional demands of each patient should be carefully considered. Factors such as age, pain, weakness, function, and loss of mobility should guide shared decision-making regarding the need for surgery. For instance, in older patients, there may be little direct correlation between anatomical deformities and functional abilities. Young and Rayan [8] found that older and less active individuals with poor radiographic scores reported an 88% satisfaction rate with their subjective clinical outcomes. These scores are based on the final dorsal angle and loss of radial length and inclination. Similarly, Diaz-Garcia et al. [9] conducted a systematic review examining outcomes and complications in distal radius fractures for patients aged ≥60 years. Their review showed that patients treated with casting had poorer radiographic outcomes; however, their functional outcomes were comparable with those of patients who underwent various surgical treatments. Therefore, the ideal timing for surgical intervention in cases of malunion of distal radius fractures remains uncertain. Jupiter and Ring [10] indicated that the outcomes of early surgery (within 14 weeks after injury) were similar to those of later surgery (beyond 14 weeks). However, they observed that patients treated earlier had an average grip strength of 42 kg compared with 25 kg for those who underwent delayed surgery. Therefore, the authors concluded that early surgery, particularly in patients with radiographic indicators of likely functional limitation, is technically simpler and reduces the overall disability duration. Other experts suggest operating as soon as malunion is detected, within 1–2 months after injury; therefore, the fracture callus can be distinguished from the cortical bone, making it easier to restore proper anatomical alignment.

Based on a review of the above studies, corrective surgery should be performed within 14 weeks if there is radiographic evidence of malunion progression and the patient is symptomatic but not elderly. The author does not view age as an absolute criterion for defining ‘elderly.’ However, the decision to proceed with surgery was based on factors such as the patient’s engagement in household tasks or the amount of hand usage.

There are two corrective surgical methods: open-wedge and closed-wedge osteotomies. In a multicenter study, Shea et al. [11] reported a series of 25 patients, Linder and Stattin [12] reported six patients, and Prommersberger et al. [13] reported 20 patients who underwent open-wedge osteotomy with an iliac bone graft. In their study, open-wedge osteotomy yielded satisfactory results.

Open-wedge osteotomies are preferred over closed-wedge osteotomies because they improve radial length and can be used to correct angular deformities in multiple directions [14].

However, the disadvantages of opening-wedge osteotomy include a higher li1kelihood of instability at the osteotomy site until full healing occurs and an increased risk of nonunion or implant failure due to axial loads and shear stresses, particularly when early wrist movement is permitted. Additionally, there are inherent risks of complications at the bone graft donor site and challenges in achieving proper reduction [7].

However, the closing-wedge osteotomy technique proposed by Wada et al. [7] and Zhang et al. [15] is an effective reconstructive procedure for treating extraarticular distal radial malunion. It is significantly better than the opening-wedge osteotomy technique regarding restoration of ulnar variance, extension-flexion arc of wrist motion, and the Mayo wrist score [7].

Pereira et al. [16] reported that a longer ulnar resection length (≥5.5 mm) significantly increases the risk of nonunion following ulnar shortening osteotomy. As mentioned above, open and closed-wedge osteotomies have advantages and drawbacks. Therefore, in this study, we present points that address the limitations of each surgical method.

Our surgical method preserves the length of the radius by achieving half the correction angle but doubling the corrective effect. It also allows for easy reduction by rotating the graft by 180° for bone grafting, expanding the bone contact area and thus promoting effective bone union in the radius. Additionally, iliac bone grafting was not required when using the resected bone for grafting. However, this method cannot maintain the radius length, requiring an additional ulnar osteotomy in all cases. This is considered a limitation of the procedure.

Furthermore, Wada et al. [7] reported that open-wedge osteotomy showed an ulnar variance of 3 mm in a cohort study, whereas closed-wedge osteotomy showed 0.2 mm of ulnar variance. According to this study, ulnar shortening may be necessary in some open-wedge osteotomy cases. However, further research on this topic is required.

The surgical method presented in this study has the advantage of shortening the length of the ulnar osteotomy and reducing the risk of ulnar nonunion. In this study, the average ulnar shortening size was 4 mm, whereas in Wada et al’s study [7], it was 6 mm. In a few articles, multivariate analysis identified a longer resection length (≥5.5 mm) as an independent risk factor for nonunion. Therefore, a shorter resection length can potentially reduce the risk of ulnar nonunion compared with conventional closed-wedge osteotomy [16].

Finally, using this surgical method, the bone obtained after the radial osteotomy was used for bone grafting. Additionally, the cancellous bone harvested from the ulnar resection was used for grafting. This reduced the need for grafting from the iliac bones and allowed surgery to be performed without general anesthesia. This method is safer for older patients because it minimizes the need for general anesthesia.

The limitation of this study was that it was performed on a small group of five patients at a single institution, which did not allow for the accumulation of sufficient clinical data. Therefore, further studies involving many patients from multiple institutions are required. This was also a retrospective study. Thus, further comparative studies are necessary to determine whether this method yields better results than existing surgical techniques.

Additionally, this surgery does not restore the radial length as effectively as open-wedge corrective osteotomy and requires additional ulnar shortening. Reduction is also not as easy as closed-wedge osteotomy, and because ulnar resection is also performed, the method does not fully have the advantages of both surgical techniques. As well, if the correction angle is small, it is challenging to use this surgical method. Based on the surgeon’s experience, when the angle falls below 10°, the sawing distance becomes too short, failing to get enough bone for rotation, making a correction angle of 10° or more preferable. Mathematically, considering the volar-dorsal depth of the radius to be between 14 and 16 mm, with a correction angle of 10°, the sawing distance is estimated at 2.5–3 mm when calculated using the tangent of 10°. If the cutting length is less than 2 mm, it may be challenging to obtain enough bone.

Finally, surgeons must rely on intuition to determine the correction angle using a C-arm. Additionally, this technique cannot be used in patients with severe osteoporosis because of poor bone quality.

Conclusion

In treating dorsal malunion of a distal radius fracture, half osteotomy and the rotational repositioning surgical technique can reduce the amount of corrective osteotomy needed for the radius compared with a closed-wedge osteotomy. It also decreases the length of additional ulnar shortening, lowers the probability of requiring additional bone grafting from the iliac bone, and reduces the need for general anesthesia. Notably, postoperative outcomes were favorable, making this an effective surgical method.

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