Current evidence in proximal humeral locking plates

Philip Borg, Matthew Welck, Tim Peckham

Basildon and Thurrock University Hospital, Department of Trauma and Orthopaedics

Epidemiology

Proximal humerus fracture is the second most common fracture of the upper extremity, following distal forearm fracture [1]. The overall prevalence is about 70 per 100 000 population/year, representing about 5% of all fractures. The prevalence rises to 405 per 100 000 population/year over the age of 70 years [2].

Concept

There is consensus that conservative treatment should be implemented in undisplaced fractures; however some debate exists on the management of comminuted 2, 3 and 4 part fractures [3].

The development of the locking plate has changed the management of many fractures. They have a number of advantages including improved fixation in osteoporotic bone, and the facilitation of reconstruction of comminuted irreducible fractures [4]. PHILOS (Proximal Humerus Internal Locking System) is part of the latest generation of locking compression plates for proximal humeral fracture fixation.

The concepts behind its use are to provide:

1. Stable fixation of the unstable proximal humerus fracture until bony union.
2. Early mobilisation of the shoulder and early active rehabilitation program.
3. Good functional outcomes and a good restoration of the activities of daily living [5].

The implant’s ability to achieve these has been debated. We ran a PubMed search looking at the most recent literature on the use of these humeral locking plates, and have summarised our findings. We looked particularly at their indications, contraindications, techniques, complications and outcomes.

Indications for use

• In the treatment of acute unstable 2, 3 and 4 part fractures and fracture dislocations.
• Non-union of fractures especially at the neck of the humerus (combined with bone grafting).
• Pathological fractures [5].

Contraindications

• Extensively comminuted humeral head fractures which cannot be adequately reconstructed.
• Fractures in immature patients.
• Local infection after previous surgery [5].

Techniques

2 different approaches are predominantly used: anterior deltopectoral approach (most common), and the minimally invasive transdeltoid lateral approach ( two minimal incisions with a lateral deltoid split and a more distal shaft incision). There is no significant difference in clinical outcome scores between the 2 approaches [6].

Proximal humerus plating by the deltopectoral approach.

Blunt mobilisation of the deltoid muscle. Suture loops through supraspinatus tendon, infraspinatus tendon, and the subscapularis tendon close to their bony insertion. Careful indirect reduction of the fracture fragments without further damage to their blood supply. Correct positioning of the LPHP (Locking Proximal Humerus Plate) on the lateral side of the humerus, approximately 5 mm below the tip of the greater tuberosity. Indirect approximation of the subcapital fracture component to the plate, by tightening a standard 3.5-mm cortical bone screw inserted into the first hole distal to the metaphyseal fracture line. Temporary fixation of the plate with 1.8-mm Kirschner wires. Fixed-angle fixation of the plate to the bone, using locking screws. Additional stabilization of the tuberosities to the plate with suture loops [5].

With regards to the removal of implants after radiographic union: In a series of 59 patients Kirchhoff et al. , (2008) found a significant improvement in clinical outcomes after plate removal, however they only suggested removal in symptomatic patients [7].

Complications

Complications in the literature include:

• Humeral head necrosis
• Delayed union/non-union
• Screw cut out with intra-articular displacement
• Implant failure
• Varus displacement (>10˚)
• Infection
• Heterotopic bone formation
• Axillary artery injury (from screws that cut out of humeral head)[8]
• Neurological injury

• Egol et al. (2008). Series of 51 patients looking at complications following PHILOS.

92% of cases had radiographic union at 3 months. Complication rate of 24% (16% screws penetrating humeral head, 2 patients had osteonecrosis, 2 patients had non union, 2 early implant failure requiring operative intervention, 1 infection, 1 heterotopic bone) [9].

• Owsley et al. (2008). Series of 53 patients. 36% of patients had radiographic signs of complication, with revision surgery performed in 13%. Complications mentioned were: screw cutout with intra-articular displacement in 23%, >10 degrees varus displacement in 25%, and osteonecrosis in two 4%. Interestingly 57% of complications occurring in patients older than 60 years of age, showing a correlation with age but not with fracture type [10].
• Risk factors for delayed union or non-union include comminution, smoking, and 3-part fracture s [11].

Outcomes

Radiological

• Shahid et al. (2008), Prospective series of 41 patients reviewed on average 21 months after operation. Radiological union achieved within 8 weeks in 40/41 fractures. The same series noted better results in younger and male patients, with the number of fracture fragments not affecting results[12].
• Kilic et al. (2008) Series of 22 patients followed up at a mean of 14 months. Union observed radiographically in 20/22 patients at 10 weeks, with one patient having to undergo autologous bone grafting for non union at 16 weeks [6].
• Moonot et al. (2007). Prospective series of 32 patients with 3 and 4 part humeral fractures, followed up at a mean of 11 months. 97% of fractures had united radiologically at a mean of 10 weeks. Mean Constant score at final review was 66.5 [13].

Functional

• Bogner et al. (2008), in a recent series of 50 patients over 70 years of age followed up at a mean of 33.8 months, treated using a minimally invasive technique. The mean Constant score of the patients with a three-part fracture was 61.2 points (35 to 87) which was 84.9% of the score for the non-injured arm. In four-part fractures it was 49.5 points (18 to 87) or 68.5% of the score for the non-injured arm [2]
• Lafamme et. al. (2008), in a recent multicenter clinical trial series of 27 patients using only minimally invasive humeral plating of fractures of the proximal humerus followed up at 1 year showed a normal Constant ( Constant-Murley Shoulder Outcome Score) and DASH (Disability Arm, Shoulder, Hand) age-adjusted score [14].
• Plecko et al. (2005), in a prospective series with 36 patients satisfactory results in 75% of patients when reviewed on average 31 months after surgery (average Constant Score of 80.7 points, average DASH Score of 18.0) [5].
• Moonot et al. (2007). Prospective series of 32 patients with 3 and 4 part humeral fractures, followed up at a mean of 11 months. Mean Constant score at final review was 66.5. No significant difference in outcome in patients above 60 years of age [13].

Conclusion

The use of locking plate technology is a useful tool in the management of proximal humeral fractures. We have outlined the concept, indications & contraindications, technique, complications and outcome. Although many studies have shown excellent radiological union, the functional scores are somewhat more varied. There are still many unanswered questions. Do these plates offer better outcomes than traditional methods? Is the procedure cost effective (cost of surgery and implant vs improvement in function)? Is there any place for the fixation of 2 part fractures to enable earlier mobilisation? An interesting comparison can be made with a recent systematic review on the use of hemiarthroplasty for proximal humeral fractures [15]. This reported an average constant score of 56.6 points (11-98) in 560 patients with only 58% of patients satisfied with the outcome.

The proximal humerus fracture remains a difficult problem to treat.

References

1. Baron, J.A., Barrett J.A., Karagas M.R. (1996) The epidemiology of peripheral fractures.

Bone . 18(3 Suppl):209S-213S.

2. Bogner, R., Hübner C., Matis N., Auffarth A., Lederer S., Resch H., (2008) Minimally-

invasive treatment of three- and four-part fractures of the proximal humerus in elderly patients

J Bone Joint Surg [Br] , 90 B 12: 1602-1607.

3. Strohm, P.C , Helwig, P ., Konrad, G ., and Südkamp, N.P . (2007) Locking plates in proximal humerus fractures. Acta Chir Orthop Traumatol Cech. 74 (6): 410-415.

4. Noelle Larson, A., and Rizzo, M. (2007) Locking Plate Technology and Its Applications in Upper Extremity Fracture Care. Hand Clinics . 23 (2): 269 – 278.

5. Plecko, M., and Kraus, A. (2005) Internal fixation of proximal humerus fractures using the locking proximal humerus plate. Oper Orthop Traumatol. 17 (1):25-50.

6. Kılıç, B ., Uysal, M ., Cınar, B.M ., Ozkoç, G ., Demirörs, H .,and Akpınar, S . (2008) Early results of treatment of proximal humerus fractures with the PHILOS locking plate. Acta Orthop Traumatol Turc. 42 (3):149-153

7. Kirchhoff, C ., Braunstein, V ., Kirchhoff, S ., Sprecher, C.M ., Ockert, B ., Fischer, F ., Leidel, B.A ., and Biberthaler, P . (2008) Outcome analysis following removal of locking plate fixation of the proximal humerus. BMC Musculoskeletal Disorders 9: 138 – 146.

8. Khunda, A., Stirrat, A. N., and Dunlop, P. (2007) Injury to the axillary artery, a complication of fixation using a locking plate . J Bone Joint Surg Br. 89 (B): 1519 - 1521.

9. Egol, K.A , Ong, C.C ., Walsh, M ., Jazrawi, L.M ., Tejwani, N.C ., and Zuckerman, J.D . (2008) Early complications in proximal humerus fractures (OTA Types 11) treated with locked plates. J Orthop Trauma. 22 (3):159-164.

10. Owsley, K.C ., and Gorczyca, J.T . (2008) Fracture displacement and screw cutout after open reduction and locked plate fixation of proximal humeral fractures. J Bone Joint Surg Am. 90 (2): 233-240.

11. Rose, P.S. Adams, C.R. Torchia, M.E. Jacofsky, D.J. Haidukewych, G.G. and Steinmann, S.P. (2007) Locking plate fixation for proximal humeral fracture s: initial results with a new implant. J Shoulder Elbow Surg. 16 (2): 202-207.

12. Shahid, R ., Mushtaq, A ., Northover, J ., and Maqsood, M . (2008) Outcome of proximal humerus fractures treated by PHILOS plate internal fixation. Experience of a district general hospital. Acta Orthop Belg. 74 (5): 602-608.

13. Moonot, P., Ashwood, N., and Hamlet, M. (2007) Early results for treatment of three- and four-part fracture s of the proximal humerus using the PHILOS plate system. J Bone Joint Surg Br. 89 (B): 1206 - 1209.

14. Laflamme, G.Y , Rouleau, D.M , Berry, G.K ., Beaumont, P.H ., Reindl, and R , Harvey E.J . (2008) Percutaneous humeral plating of fractures of the proximal humerus: results of a prospective multicenter clinical trial. J Orthop Trauma. 22 (3):153-158.

15. Kontakis, G., Koutras, C., Tosounidis, T.,Giannoudis, P. (2008) Early management of proximal humeral fractures with hemiarthroplasty: A systematic review JBJS 90-B. 1407-13