Fractures of the distal radius are among the most frequent fractures that orthopedic surgeons treat on a daily basis. A cast or dorsal slab can be applied and manipulation for rapid reduction is another conservative treatment option. However, the outcomes are often negative due to impaired function ^[1]. Percutaneous K-wire fixation or external fixator application, as well as manipulation for closed reduction, are examples of minimally invasive treatments. In distal radius fractures treated with close reduction, K-wire fixation, and external fixation, several studies showed acceptable anatomical and functional outcomes. However, they have also noted a significant rate of pin tract infection and nerve injury ^[2]. Infection, delayed union, and non-union can arise from extensive soft-tissue dissection and periosteal stripping caused by traditional open reduction with internal fixation. The recently established technique of minimally invasive plate osteosynthesis (MIPO) has been shown in the literature to reduce bone fragment vascularity damage and soft tissue stripping. Lower limb fractures are often treated using MIPO, however, upper limb fractures are less frequently treated with this technique ^[3]. This study aims to evaluate the functional result and complications associated with the MIPO approach for treating distal radius fractures utilizing the palmar locking plate and two types of incisions ^[4].

This was a prospective research that took place between November 2022 and April 2023 and involved 20 patients with distal radial fractures (12 right, 8 left) who were treated by the modified MIPO technique with a palmar locking plate. The Ethical Committee of our institute granted us ethical authorization to undertake this investigation. After explaining the study to each participant, they signed a written informed consent. The study comprised skeletally mature patients with extraarticular and minimally comminuted intra-articular fractures. Patients with pathological fractures, ipsilateral fractures of other upper limb bones, open fractures, severe comminuted intra-articular fractures, skeletal immaturity, pre-existing stiffness of ipsilateral joints, dorsal Barton, or severe dorsal comminution were not allowed to participate in the study. Anteroposterior (AP) and lateral (LAT) views of the affected wrist were among the specific X-rays that were part of the initial workup for the instances. A computed tomography scan was necessary for pre-operative planning in around six patients due to intra-articular extension and comminution.

Operative procedure

The patient was given under regional anesthesia (supra-clavicular block) and put on the operating table in the supine position. Fluoroscopy was used to conduct manual reduction. After a good reduction was obtained, one or two 1.5 mm K-wires were placed obliquely from the radius’s styloid process to the proximal ulnar side of the distal radius to sustain the reduction; occasionally, the K-wires were also put from the other direction. A type C fracture requires the addition of another K-wire that runs parallel to the distal radius’s articular surfaces. The two skin incisions were each 2 cm in length. In patients whose articular surface of the distal radius was within 1 cm of the primary fracture surface, a distal skin incision was done along the proximal wrist crease. If this distance exceeded 1 cm, a distal skin incision was done parallel to the flexor carpi radialis (FCR) on the radial side along the proximal wrist crease. The radial artery was retracted ulnar ward, and the FCR tendon was retracted radially after incising the superficial and deep fascia on the radial side. To reveal the pronator quadratus, the flexor pollicis longus was then pulled back to the ulnar side. A longitudinal incision was made in the middle of the distal part of the pronator quadratus. For patients with partial pronator quadratus damage, this incision was not necessary. The incision should be performed on the fracture end to aid reduction under direct view for a small number of patients who have dissatisfied closed reduction. Extraperiosteally, a suitable oblique palmar locking plate was placed via the incision. Following adequate plate fixation and fracture reduction, a 2 cm proximal skin incision was done on the FCR’ radial side. The flexor pollicis longus was dissected, and the ulnar artery was retracted ulnar ward to expose the proximal end of the locking plate for proper placement and fixation. After satisfactory fixation, the incisions were closed in layers (Fig. 1a and b).

After surgery, the forearm was kept elevated, and on the first post-operative day, active and passive finger motions were initiated. Physiotherapy was initiated immediately in most patients. In cases of older patients suffering from osteoporosis, the limb was immobilized in a posterior slab until the sutures were removed. On the first post-operative day, range-of-motion exercises for the shoulders, elbows, and fingers were started. It was established how much wrist dorsiflexion and palmar flexion the patient could tolerate. It was carried out immediately in young patients with a stable fracture pattern and solid fixation. However, when sutures were taken out, wrist motions were started in patients with osteoporosis or complicated fracture patterns. In the hospital, patients were closely monitored for any acute post-operative events and adherence to physical therapy was documented. A number of criteria were used to evaluate the patients. The impact of surgical techniques and intraoperative factors was studied. Bone union was evaluated using radiographs at each follow-up, and functional results were monitored using the disabilities of the arm, shoulder, and hand (DASH) score. Blood loss was assessed by counting the number of soiled sponges and the amount of fluid collected in the suction container at the conclusion of the procedure subtracted by the amount of wash given. The fluoroscopy exposure was calculated from the first shoot taken on the image intensifier to the last one, and surgical duration was measured from the incision to the closure. The radiographic evaluation was made by comparing the preoperative and post-operative volar tilt, radial height, and radial inclination. These were assessed at immediate post-operative, 12 weeks, and 24 weeks and documented. The fracture site union was seen at the fracture site in both the AP and LAT views. It might be seen on X-rays as well. Non-union was defined as 6 months without any delay. Union was noted at the end of 3 months. Cortical union was used as a measure to judge fracture union. The DASH score was used to assess functional abilities (Fig. 2).

There were 12 females and 8 males (Fig. 3). The mean time from injury to surgery was 7 days (range 0.5 h‑10 days). They were all closed fracture and were classified according to the Association of Osteosynthesis/Association for the Study of Internal Fixation system, including type A2 (n = 4), type A3 (n = 3), type B1 (n = 4), type B3 (n = 5), type C1 (n = 2), and type C2 (n = 2). All 20 patients were followed. Eleven patients obtained excellent results, seven cases had good results and two patients had moderate effects up for an average time of 6 months. The average DASH score was about 10.2. The average DASH score was about 10.2. None of the patients had poor results, thus, excellent and good results were seen in 90% of patients and fair results in 10% of the patients (Fig. 4).

The degree of dorsiflexion on average was 64°, palmar flexion was 80°, radial deviation was 15° and ulnar deviation was 35°. One patient had delayed wound healing in the proximal wrist crease. No damage to neurovascular structures such as the radial artery and median nerve injury occurred in all 20 patients postoperatively. Three patients had postoperative wrist pain for 3 months which was resolved on physiotherapy exercises.

MIPO has been used to repair fractures in a number of long bones ^[5]. MIPO involves less periosteal stripping and soft-tissue incision than standard open reduction and internal fixation (ORIF) ^[6]. In this case series, we have tried to examine the advantages of the MIPO technique in distal radius fractures and asses if it may result in improved functional and radiological outcomes. If distal radius fractures are not treated with adequate articular surface reduction and a firm, rigid fixation, they might lead to a variety of wrist issues ^[7]. After the patients received minimally invasive treatment, we followed up on the functional results and complications. In our case series, motor vehicle trauma was the most frequent cause of distal end radius fractures, followed by a domestic fall, suggesting that this is the most frequent mechanism of distal end radius fractures ^[8]. Inadequate articular reduction caused by external fixators is associated with stiffness and other complications like complex regional pain syndrome. Soft-tissue problems may arise from more thorough soft-tissue dissection that occurs with open reduction and plating ^[9]. MIPO does not have the risk of any of these challenges. Our study’s functional outcome was excellent, even better than that of prior studies that looked at open reduction and fixator application for distal radius fractures. When we compared our DASH score values at 3 and 6 months to those from previous research, such as Ravi et al., we found that we were on the right track with a reported average DASH score <10, compared to 10.2 in their study. One of the anticipated disadvantages of the MIPO technique for distal radius fracture repair is the possibility of inadvertent harm to the median nerve, its palmar cutaneous branch, or possibly the radial artery because of the minimal exposure ^[10]. However, in our research, we were aware of the danger zones and meticulously elevated the periosteum and respected the arterial connections to the FCR tendon to ensure that both the artery and nerve remain uninjured. The disadvantage of our study MIPO technique was not compared to a control group. Further advantages of our study include no follow-up loss and a single investigator, which prevents observer bias. The fact that our sample size was small compared to previous research is another drawback ^[11].

At the conclusion of this study, we highlight the advantages of this procedure, benefits in terms of safety and viability, since it eliminates the need for specialized instruments, challenging implants, or continuous radiography monitoring. MIPO offers several advantages over conventional distal radius fixation techniques, particularly in preserving soft tissue and promoting biological healing. By minimizing periosteal stripping and soft tissue disruption, MIPO maintains the fracture hematoma, enhancing natural bone healing and reducing complications such as nonunion. The smaller incision leads to less postoperative pain, faster recovery, and improved cosmetic outcomes. In addition, MIPO lowers the risk of tendon irritation and median nerve injury, which are common with volar plate fixation. It provides stable fixation, particularly in osteoporotic and comminuted fractures, while reducing the risk of infection and hardware-related complications. The indirect reduction technique prevents excessive manipulation of fracture fragments, reducing malalignment risks. While MIPO requires fluoroscopic guidance and has a learning curve, it offers a superior balance of stability, function, and soft-tissue preservation. Overall, MIPO is an excellent alternative for complex distal radius fractures, ensuring faster rehabilitation with fewer complications. MIPO for distal radius fractures is gaining popularity because it balances stability, soft tissue preservation, and faster recovery. Unlike routine ORIF, which requires extensive soft tissue dissection, MIPO minimizes periosteal stripping, preserving blood supply and promoting natural healing. This technique is particularly beneficial in osteoporotic and comminuted fractures where excessive handling can compromise bone integrity. Compared to routine volar plate fixation, MIPO reduces complications such as flexor tendon irritation, median nerve compression, and infection risk. The smaller incision results in better cosmetic outcomes, less postoperative pain, and quicker rehabilitation. In addition, MIPO maintains fracture alignment with minimal disruption, leading to lower chances of malunion. Although it requires advanced surgical skills and fluoroscopic guidance, MIPO offers superior functional outcomes with fewer complications. It is especially advantageous in complex fractures where traditional methods may lead to excessive tissue damage or delayed healing.

MIPO using a palmar locking plate is an effective and safe technique for treating distal radius fractures. It minimizes soft tissue disruption, preserves vascularity, and provides stable fixation, leading to improved functional outcomes and faster recovery. This technique reduces complications associated with traditional open reduction and external fixation, making it a promising alternative for selected patients. However, careful surgical planning and expertise are essential to avoid potential neurovascular injury. Further comparative studies with larger sample sizes are needed to establish its superiority over conventional methods.