A study of the functional assessment of the outcomes of proximal humerus fractures treated with the proximal humerus internal locking system

INTRODUCTION

Proximal humerus fractures constitute nearly 5% of all fractures and are a major cause of disability, especially among elderly individuals due to osteoporosis and increased risk of falls.¹ In younger age groups, these fractures usually result from high-energy trauma such as road traffic accidents.² With rising life expectancy, their incidence is steadily increasing.³ Minimally displaced fractures can be treated conservatively however, displaced and unstable fractures often require surgical intervention.⁴ Traditional fixation devices such as K-wires and plates are associated with complications like screw loosening, non-union and implant failure, particularly in osteoporotic bone.^5,6 The PHILOS plate was developed to provide stable angular fixation through locking screws, minimize soft-tissue damage, secure tuberosity fixation using suture-holes and allow early mobilisation, which is crucial for optimal functional recovery.^7,8 Nevertheless, the literature reports variable outcomes depending on fracture type, bone quality and surgical expertise.^9,10 The present study evaluates the functional and radiological outcomes following PHILOS plating in displaced proximal humerus fractures treated at a tertiary care institute in India.

METHODS

Study design

Prospective observational study conducted from July 2020 to July 2021 at B. J. Government Medical College and Sassoon General Hospital, Pune.

Inclusion criteria

Age>18 years, Displaced 2-part, 3-part and 4-part proximal humerus fractures

Exclusion criteria

Open fractures, undisplaced fractures, isolated tuberosity fractures, associated neurovascular injury, severe medical comorbidities preventing surgery

Surgical procedure

All cases underwent open reduction and internal fixation using PHILOS plating via a standard deltopectoral approach under general anaesthesia. Temporary fixation was achieved using K-wires or sutures, followed by locking screw placement. Rotator cuff sutures were passed through plate eyelets for tuberosity stability. Passive mobilisation was started early based on patient tolerance.

Follow-up and outcome measurements

Patients were followed at 2, 6, 8 and 12 weeks with radiographs to assess union. Functional outcomes were assessed using Constant–Murley Score at 12 weeks.

Statistical analysis

Data were analysed using IBM SPSS Statistics for Windows, Version 26.0.

RESULTS

The study included 53 patients with a mean age of 50 years, predominantly males (81%). Road traffic accidents were the most common mode of injury (58.5%), followed by domestic falls (41.5%). The majority of fractures were 3-part injuries (62%), indicating an overall higher incidence of more complex fracture patterns in the study population.

The average operative duration was 112 minutes, reflecting the technical demand of the procedure. Most patients (96%) achieved radiological union by 12 weeks, demonstrating a high success rate of fixation stability.

Postoperative complications were few and included superficial wound infections (5.7%) and implant failure (1.9%). These findings highlight that PHILOS plating offers reliable fixation with a low complication profile.

At 12-week follow-up, functional assessment using the Constant–Murley Score showed that 90.5% of patients achieved moderate to good outcomes. Specifically, 24.5% demonstrated good recovery while 66% exhibited moderate functional performance. Only 9.5% had poor outcomes, with a mean constant score of 65.66. These results suggest satisfactory short-term functional restoration following PHILOS fixation.

DISCUSSION

The present study demonstrates the effectiveness of PHILOS plating as a reliable method for managing displaced proximal humerus fractures. The high radiological union rate (96% at 12 weeks) reflects the enhanced stability provided by the locking plate design, particularly beneficial in osteoporotic bone.^2,5

Functional outcomes were predominantly moderate to good, comparable to previous literature showing better results in younger and more compliant patient groups.^7,9,10 Early mobilisation helped reduce shoulder stiffness and improved recovery. Complication rates were low and mainly minor. Implant failure occurred in one patient, possibly due to technical difficulty or compromised bone quality. The superficial infections responded well to antibiotic therapy.

Limitations

Limitations include a short follow-up period and non-comparative design, which do not capture late complications like avascular necrosis. A multicentric randomised study with long-term follow-up is suggested for further validation.

CONCLUSION

PHILOS plating offers stable fixation, early mobilisation and satisfactory short-term functional outcomes with minimal complications in displaced proximal humerus fractures. It remains a preferred method of surgical management, especially in osteoporotic bone.

Funding: No funding sources

Conflict of interest: None declared

Ethical approval: The study was approved by the Institutional Ethics Committee

REFERENCES

1. 1. Geiger EV, Maier M, Kelm A, Wutzler S, Seebach C, Marzi I. Functional outcome and complications following PHILOS plate fixation in proximal humeral fractures. Acta Orthop Traumatol Turc. 2010;44(1):1-6.
2. 2. Lind T, Krøner K, Jensen J. The epidemiology of fractures of the proximal humerus. Arch Orthop Trauma Surg. 1989;108(5):285-7.
3. 3. Kannus P, Palvanen M, Niemi S, Parkkari J, Järvinen M, Vuori I. Osteoporotic fractures of the proximal humerus in elderly Finnish persons: sharp increase in 1970-1998 and alarming projections for the new millennium. Acta Orthop Scand. 2000;71(5):465-70.
4. 4. Park MC, Murthi AM, Roth NS, Blaine TA, Levine WN, Bigliani LU. Two-part and three-part fractures of the proximal humerus treated with suture fixation. J Orthop Trauma. 2003;17(5):319-25.
5. 5. Ogiwara N, Aoki M, Okamura K, Fukushima S. Ender nailing for unstable surgical neck fractures of the humerus in elderly patients. Clin Orthop Relat Res. 1996;(330):173-80.
6. 6. Resch H, Povacz P, Fröhlich R, Wambacher M. Percutaneous fixation of three- and four-part fractures of the proximal humerus. J Bone Joint Surg Br. 1997;79(2):295-300.
7. 7. Kiliç B, Uysal M, Cinar BM, Ozkoç G, Demirörs H, Akpinar S. Proksimal humerus kiriklarin PHILOS plaği ile tedavisinde erken dönem sonuçlarimiz [Early results of treatment of proximal humerus fractures with the PHILOS locking plate. Acta Orthop Traumatol Turc. 2008;42(3):149-53.
8. 8. Nho SJ, Brophy RH, Barker JU, Cornell CN, MacGillivray JD. Management of proximal humeral fractures based on current literature. J Bone Joint Surg Am. 2007;89(3):44-58.
9. 9. Gerber C, Werner CM, Vienne P. Internal fixation of complex fractures of the proximal humerus. J Bone Joint Surg Br. 2004;86(6):848-55.
10. 10. Thyagarajan DS, Haridas SJ, Jones D, Dent C, Evans R, Williams R. Functional outcome following proximal humeral interlocking system plating for displaced proximal humeral fractures. Int J Shoulder Surg. 2009;3(3):57.