Correction of major humeral deformity from acquired ricket using a 3D personalized osteotomy guide

Rickets is a disorder of bone mineralization that can lead to complex skeletal deformities, posing significant challenges in surgical management. Although most commonly associated with nutritional deficiencies in childhood, rickets may persist into adulthood, complicating corrective procedures due to altered bone quality and irregular bony architecture. While lower limb deformities are frequently encountered, upper limb involvement is rare and often underreported. In particular, major deformities of the humerus in the context of rickets are seldom described.

In this report, we present the case of an adult male with a major humeral deformity secondary to acquired rickets. The abnormal bone mineralization associated with his condition required meticulous preoperative planning and a tailored surgical approach. We successfully addressed the deformity using a 3D personalized guide osteotomy, illustrating how modern patient-specific tools can overcome the challenges posed by complex bony pathologies. This case emphasizes the surgical difficulties inherent in managing deformities due to compromised bone quality and highlights the potential benefits of integrating advanced 3D planning techniques into orthopedic practice.

Case report

A 31-year-old male patient presented with chronic left shoulder pain. The patient is known to have vitamin D-resistant rickets, which has caused deformities in the lower limbs. He had femoral and tibial osteotomy corrections performed during childhood. He works as a mover and is right-handed. The patient had received three corticosteroid injections prior to the consultation, with no benefit.

Prior to surgery, the patient underwent comprehensive conservative management, including physiotherapy, nonsteroidal anti-inflammatory drugs, and corticosteroid injections. Despite these interventions, his pain and functional limitations persisted. This failure of nonsurgical care, combined with his deteriorating shoulder function, prompted further evaluation and ultimately led to the decision for surgical correction.

Clinically, we observed a forward flexion of 100° (compared to 150° on the right), external rotation of 30° (same as on the right), and abduction of 60° (compared to 80° on the right). The Hawkins test was highly positive, while other examinations were normal. Standard radiography showed a narrowed subacromial space due to significant diaphyseal bowing in both anteroposterior and profile views (Figs. 1 and 2). A magnetic resonance imaging study confirmed the integrity of the rotator cuff.

Figure 1.

AP view: lateral bowing. AP, anteroposterior.

Figure 2.

Profil view: sagittal bowing.

After the failure of conservative treatment, it was decided to proceed with a correctional osteotomy using a 3D printed personalized guide. The aim of the surgery was to relieve pain, restore original rotation, forward flexion, and abduction, and prevent secondary rotator cuff rupture.

A biplanar oblique osteotomy was chosen. We used a computed tomography (CT) scan of the humerus, which was sent to "My Osteotomy-Medacta" (Medacta, Castel San Pietro, Switzerland) for printing the 3D personalized guide (Figure 3, Figure 4, Figure 5).

Figure 3.

Humeral preopoperative deformity.

Figure 4.

3D printed guide.

Figure 5.

Preoperative and postoperative plan.

The patient was positioned in a beach chair, and a delto-pectoral approach was chosen. We also performed a tenodesis of the biceps with acromioclavicular resection. The 3D guide was correctly positioned and fixed with a K-wire (Figs. 6, 7, 8, a and b). The osteotomy was then performed.

Figure 6.

Guide positioning.

Figure 7.

Plate positioning after osteotomy.

Figure 8.

(a) 3D guide positioning. (b) 3D guide positioning.

Once derotation was done, we placed a Philos (J and J MedTech, New Brunswick, NJ, USA) plate fixated with 9 proximal locking screws and 4 distal locking screws (Fig. 9). The rehabilitation protocol was to protect the osteotomy during 3 weeks of passive and slight mobilization. The patient experienced minimal pain in the early postoperative period. Follow-up at 3 months showed that the patient was free of pain, with active forward flexion of 120°, external rotation of 30°, and abduction of 60°. Follow-up at 18 months demonstrated complete recovery with active forward flexion of 170°, external rotation of 40°, and abduction of 160°. To achieve this, we collaborated closely with the firm's engineering team. A 3D model of the pathological humerus (Fig. 3) is obtained using the preoperative CT scan. The correct definition of the pathological deformation of the humerus was achieved using the representation of a standard humerus (indeed, in our case, we cannot rely on the contralateral side since both humeri are affected in this type of pathology).

Figure 9.

Final plate positioning.

The superimposition of the pathological bone (orange and pink) with the mirrored image of the healthy humerus (green) allows for quantification of the malposition in different axes. This makes it possible to develop a cutting guide to correct this malposition (Figs. 4 and 5).

The osteotomy plane is defined in the planning software to simulate the osteotomy. The bone is cut into two fragments, separating the orange and pink areas using the cutting guide. The cutting guide is fixed with pins (Figs. 5 and 6).

Once the osteotomy is performed, we use a predefined reduction guide, which is fixed using the pins already in place (from the cutting guide). Reduction is simulated by aligning the pathological humerus (pink) with the mirrored image of the healthy bone (green). A custom-made plate is then placed, allowing for osteosynthesis of the osteotomy in the desired reduction position (Fig. 7).

The patient was positioned in a beach chair, and a delto-pectoral approach was chosen. We also performed a tenodesis of the biceps with acromioclavicular resection. The 3D guide was correctly positioned and fixed with a K-wire (Figs. 6, 7, 8, a and b). The osteotomy was then performed. Once derotation was done, we have placed a Philos plate fixated with 9 proximal locking screws and 4 distal locking screws (Figs. 9 and 10). We allowed the patient to perform gentle passive mobilization during the first three weeks postoperatively. The patient had minimal pain in the early postoperative period. At the 3-month follow-up, the patient was pain-free, with 120° of active forward flexion, 30° of external rotation, and 60° of abduction. The 18-month follow-up showed complete recovery, with 170° of active forward flexion, 40° of external rotation, and 160° of abduction (Fig. 11, a and b). It is important to highlight that our patient regained better function on the operated side compared to the contralateral side, which was initially less deformed but also pathological.

Figure 10.

Day 1 control.

Figure 11.

(a) 18 months follow-up. (b) 18 months follow-up.

Discussion

Anatomy and early impingement

Subacromial impingement occurs when the greater tuberosity of the humerus conflicts with the acromion, leading to pain and restricted motion. In our patient, this was driven by abnormal humeral morphology, specifically an increased neck-shaft angle and excessive humeral retroversion.^3,5 These deformities disrupted scapulohumeral rhythm, altered biomechanics, and contributed to progressive shoulder dysfunction.⁷ To address this, we performed a corrective osteotomy that indirectly achieved subacromial decompression. By modifying the humeral neck-shaft angle and retroversion, we expanded the subacromial space, reduced mechanical conflict, and restored a more physiological range of motion, preventing secondary rotator cuff pathology.

Humeral neck-shaft angle

Our patient exhibited a significantly increased neck-shaft angle (170°), resulting in varus malalignment and compromised shoulder mechanics.⁴ This abnormal configuration restricted forward flexion and led to compensatory scapular movement, increasing mechanical strain on the joint. Correction of the neck-shaft angle was essential to improve overall shoulder function and reduce impingement symptoms.

Humeral retroversion

Excessive humeral retroversion further contributed to impingement by positioning the humeral head in excessive external rotation. This caused the greater tuberosity to impinge against the acromion during elevation, limiting motion and increasing pain. Studies have shown that the average retroversion angle of the humeral head ranges from 30° to 35° on the dominant side and 26° to 31° on the nondominant side.⁴ In our patient, the exaggerated retroversion disrupted normal glenohumeral mechanics, necessitating correction to restore rotational balance and improve congruity.

The patient-specific 3D guide enabled accurate preoperative planning and execution, ensuring that the corrected alignment was both anatomical and biomechanically sound. This correction optimized alignment, alleviated impingement, and enhanced shoulder function. Collaboration with engineers facilitated customization of the osteotomy, demonstrating the value of advanced surgical planning in complex orthopedic cases.

Anatomical reconstruction was planned using reference parameters from average normal humeri, rather than the patient's contralateral side, as the pathology is bilateral. The engineers relied on standardized datasets of normal humeral anatomy to define the correction parameters.^8,10

Anatomical reconstruction planning

Anatomical reconstruction was planned using reference parameters from average normal humeri, rather than the patient's contralateral side, as the pathology is bilateral. The engineers relied on standardized datasets of normal humeral anatomy to define the correction parameters.

A preoperative CT scan is performed to facilitate this. Conventional planning of corrective osteotomy based on standard radiographs has limited precision. The Medacta planning system also allows for a virtual predetermination of the osteotomy line and the position of the screws for the patient-specific guide. This enables precise and predictable planning for treatment. Anatomical adjustment of the implant is guaranteed, and axial and rotational deformities are taken into account.^1,2,11

Customized cutting guides

In the next step, the creation of custom-made cutting guides improves precision for treating these demanding pathologies. Previous studies have evaluated and encouraged the development of patient-specific cutting guides, developed from computer-assisted 3D simulation systems. This technology allows for the planning of reliable corrective osteotomies and simplifies surgery. Oka et al concluded, in a study of 16 adults, that there was improved precision in osteotomies performed with custom-made cutting guides, with a correction error of less than 1°. Byrne et al analyzed five children and found an average correction error of 1.63°. The simplicity of the surgical procedure is another advantage of this technique. Correction and internal fixation are performed simultaneously by placing the plate and inserting the screws into the holes predrilled using the guide before the osteotomy.⁶

Operational efficiency

Regarding operative time, properly executed planning allows for optimal preparation for the surgical procedure and anticipation of potential complications. Zhang et al demonstrated a significant reduction in operative times in the group operated on with the aid of 3D planning for corrective cubitus varus osteotomies in adolescents. Thus, infection risks, anesthesia duration, and the risks of pressure sores from the operating table are reduced.^9,13

3D personalized guide solution

The 3D personalized guide solution is highly accurate and can restore physiologic anatomy. Planning and discussion with engineers lead to the perfect positioning of the future plate to restore the patient's function. The surgery is also faster, more precise, and with less blood loss.¹²

Conclusion

To our knowledge, this is the first report of a case of a rare humerus deformation due to vitamin D-resistant rickets treated with 3D personalized osteotomy guide. This pain was associated with a reduced range of motion and was not relieved by conservative treatments. An innovative approach using a 3D personalized guide for osteotomy, based on CT imaging, was planned to correct the deformity. The surgery aimed to alleviate pain, restore movement, and prevent rotator cuff damage.

The procedure involved a biplanar oblique osteotomy with a 3D guide for precise bone cutting, followed by fixation with a Philos plate. The surgery resulted in less pain, more precision, and increased function compared to traditional methods 18 months postoperative, the patient showed significant improvement in range of motion and was free from pain. The case highlights the potential of using 3D printing technology for personalized surgical planning and intervention in orthopedics, particularly for complex cases where standard procedures may not suffice.

Disclaimers:

Funding: No funding was disclosed by the authors.

Conflicts of interest: The authors, their immediate families, and any research foundation with which they are affiliated have not received any financial payments or other benefits from any commercial entity related to the subject of this article.

Patient consent: The patient provided informed consent for the use of his clinical data and images for publication and presentation.