Application of pre-contoured anatomic locking plate for treatment of humerus split type greater tuberosity fractures: A prospective review of 68 cases with an average follow-up of 2.5 years

Additional cuff suture provides mechanical advantage for fixation of split-type greater tuberosity fracture of humerus

PURPOSE

Split type of greater tuberosity fracture has variety of surgical treatment options. This study aimed to compare the biomechanics property of additional cuff suture and other fracture fixation techniques.

METHODS

Fifteen porcine humeri were categorized into three groups of fixation techniques those were proximal humeral internal locking system (PHILOS) plate with 2 cuff sutures, nonlocking (conventional, 3.5 mm) T-plate with 2 cuff sutures and T-plate with washer that had additional cuff suture (novel technique). Fracture was created by greater tuberosity osteotomy with 50˚ inclination to the line of surgical neck and then fixed with different prescribed techniques. Displacement of fracture site was measured with universal testing machine. The maximum forces to produce 3 mm, 5 mm of displacement and load to failure were recorded.

RESULTS

The average loads to reach 3 mm, 5 mm displacement and failure were 30.8 N, 45.4 N and 161 N for nonlocking T-plate; 76.6 N, 99.2 N and 144 N for PHILOS plate; 95.8 N, 120 N and 197 N for novel technique. The differences among three groups were significant in load to displacement at 3 and 5 mm (but not significant in load to failure). For load to reach 3- and 5-mm displacement, PHILOS plate and novel technique were significantly stronger than nonlocking T-plate (P < 0.05). For load to reach 3 and 5 mm displacement, novel technique was stronger than PHILOS plate but not significant (P > 0.05). For load to failure, novel technique was stronger than nonlocking plate and PHILOS plate but not significant (P < 0.05).

CONCLUSION

The important factors affecting the strength of fracture fixation are type of plate and numbers of suture augmentation that tie to the plate. Fixation with additional cuff suture showed the superior biomechanics of load to reach 3 mm, 5 mm displacement with better load to failure compared with PHILOS plate and conventional T-plate alone.

Biomechanical comparisons of hook plate and screw fixations in split-type greater tuberosity fractures of the humerus

BACKGROUND

Screws and plate are commonly utilized for the fixation of split-type humeral greater tuberosity (GT) fractures. However, the mechanical properties of these 2 types of fixation methods have not been compared directly. The aim of the present study was to evaluate the classic 2 screws fixation with hook locking plate from a mechanical perspective.

METHODS

Sixteen synthetic humerii (Sawbones Pacific Research Laboratories, Vashon, WA, USA) were divided into 2 groups. An osteotomy was performed to simulate a split-type GT fracture. Group A (n = 8) was fixed with 2 standard parallel screws. Group B (n = 8) was fixed with a hook plate. Each specimen was tested with traction force at 45° shoulder abduction. Following the 20-N preload, a 500-cycle loading test was applied with a force ranging from 20 to 200 N (valley/peak), and the interfragmental displacement was measured periodically at intervals of 100 cycles. Finally, all the specimens were pulled with destructive force at a rate of 5 mm/min until catastrophic failure.

RESULTS

The hook plate exhibited greater construct stiffness than the screw fixation (63.2 ± 6.1 N/mm vs. 40.9 ± 3.4 N/mm, P < .001). All of the specimens completed the entire cyclic loading test without catastrophic failure, and the fragment displacement after 500 cycles was 0.4 ± 0.2 mm for the hook plate and 2.1 ± 0.3 mm for screw fixation, which was statistically lower in the plate group (P < .001). In terms of failure load, the hook plate group exhibited a significantly greater value than the screw group (770.6 ± 94.6 vs. 427.5 ± 45.1 N/mm, P < .001). The failure modes of both fixation methods were distinct.

CONCLUSION

In humeral GT fracture fixation, hook plate fixation appears to offer greater construct stiffness and failure load while maintaining fragment stability to resist a physiological traction force. The current study provides support from a mechanical perspective for the clinical application of the hook plate.

A new biomechanical classification system for split fractures of the humeral greater tuberosity: guidelines for surgical treatment

Background

Split fractures of the humeral greater tuberosity (HGT) are common injuries. Although there are numerous surgical treatments for these fractures, no classification system combining clinical and biomechanical characteristics has been presented to guide the choice of fixation method.

Methods

We created a standardised fracture of the HGT in 24 formalin-fixed cadavers. Six were left as single-fragment fractures (Group A), six were further prepared to create single-fragment with medium size full-thickness rotator cuff tear (FT-RCT) fractures (Group B), six were cut to create multi-fragment fractures (Group C), and six were cut to create multi-fragment with FT-RCT fractures (Group D). Each specimen was fixed with a shortened proximal humeral internal locking system (PHILOS) plate. The fixed fractures were subjected to load and load-to-failure tests and the differences between groups analysed.

Results

The mean load-to-failure values were significantly different between groups (Group A, 446.83 ± 38.98 N; Group B, 384.17 ± 36.15 N; Group C, 317.17 ± 23.32 N and Group D, 266.83 ± 37.65 N, P < 0.05). The load-to-failure values for fractures with a greater tuberosity displacement of 10 mm were significantly different between each group (Group A, 194.00 ± 29.23 N; Group B, 157.00 ± 29.97 N; Group C, 109.00 ± 17.64 N and Group D, 79.67.83 ± 15.50 N; P < 0.05). These findings indicate that fractures with a displacement of 10 mm have different characteristics and should be considered separately from other HGT fractures when deciding surgical treatment.

Conclusions

Biomechanical classification of split fractures of the HGT is a reliable method of categorising these fractures in order to decide surgical treatment. Our findings and proposed system will be a useful to guide the choice of surgical technique for the treatment of fractures of the HGT.

Surgical fixation of isolated greater tuberosity fractures of the humerus- systematic review and meta-analysis

OBJECTIVES

A systematic review was undertaken based on PRISMA guidelines to study the results of surgical treatment of Greater Tuberosity fractures of the Humerus by different techniques (Open, Percutaneous or Arthroscopic) and using different fixation devices (Sutures, Screws and Plates).

DATA SOURCES

Literature searches were performed for studies in English on four online databases (MEDLINE®, Embase®, Ovid® Emcare and CINAHL®) using a pre-planned search strategy.

STUDY SELECTION

Studies were screened against pre-decided inclusion and exclusion criteria. 24 articles were eligible for inclusion involving 562 patients in all.

DATA EXTRACTION

A template was used for collection of relevant data regarding the study design, demographics, fracture characteristics, surgical techniques and implants used, outcomes, complications and re-operations. Methodological quality was assessed using a modified Coleman Methodology Score.

DATA SYNTHESIS

Pooled analysis was conducted for (1) complications/reoperations of different devices; and (2) reported results using standard outcome measures of various techniques. Results were pooled using inverse variance method. When pooling proportions, we used arcsine transformation to account for zero events.

CONCLUSION

Use of screws was associated with higher rates of total complications (23.7%) as well as reoperations (13.2%), compared to sutures (14.2%; 2.6%) and plates (10.6%; 4.1%). In a subgroup analysis, use of low-profile plates (LPPs) was associated with the lowest rates of total complications (4.97%). The superiority of any surgical technique could not be established using the pooled Constant or ASES scores because there was lack of uniformity in the reporting of outcome measures. Our analysis of complications of the various fixation devices dissuades the use of screws and favours the use of low-profile plates. There is a need for prospective studies comparing arthroscopic suture fixation with open low-profile plate fixation of GT fractures.

A new low-profile anatomic locking plate for fixation of comminuted, displaced greater tuberosity fractures of the proximal humerus

BACKGROUND

Although various implants exist for the fixation of isolated greater tuberosity fractures, few implants are specifically designed for such fractures. The purpose of this study was to investigate the clinical and radiologic outcomes of open reduction-internal fixation with a low-profile anatomic locking plate for comminuted greater tuberosity fractures of the proximal humerus.

METHODS

From November 2012 to February 2018, 24 patients with displaced and comminuted isolated greater tuberosity fractures were treated with the new low-profile anatomic locking plate. To determine clinical outcomes, we evaluated active range of motion; the visual analog scale pain score; the Constant-Murley score; the Disabilities of the Arm, Shoulder and Hand score; radiographs; and complications.

RESULTS

In all cases, a mean follow-up period of 29.3 months (range, 18-48 months) was completed. All patients achieved bone union with a mean healing time of 11.3 weeks (range, 8-16 weeks). The mean Constant-Murley score was 91.1 points (range, 69-100 points), with a rate of good to excellent results of 95.8%. The average Disabilities of the Arm, Shoulder and Hand score was 9.9 points (range, 2-25 points), and the mean visual analog scale pain score was 1.1 points (range, 0-4 points). Mean active forward flexion, abduction, external rotation, and internal rotation (level) were 157°, 152°, and 40°, and T11, respectively. Postoperatively, 1 patient had persistent shoulder stiffness, and 1 patient had recurrence of shoulder dislocation because of a falling injury during badminton. No serious complications such as subacromial impingement, malunion, nonunion, loss of reduction, or implant failure occurred.

CONCLUSIONS

The new low-profile anatomic locking plate was useful for the treatment of comminuted isolated greater tuberosity fractures as it provided reliable stability and satisfactory radiographic and functional results. The described technique is a simple and effective method and provides a new reliable option for the treatment of isolated greater tuberosity fractures.

Augmented cerclage wire improves the fixation strength of a two-screw construct for humerus split type greater tuberosity fracture: a biomechanical study

Background

Poor functional outcome can result from humeral greater tuberosity (GT) fracture if not treated appropriately. A two-screw construct is commonly used for the surgical treatment of such injury. However, loss of reduction is still a major concern after surgery. To improve the biomechanical strength of screw fixation in GT fractures, we made a simple modification of the two-screw construct by adding a cerclage wire to the two-screw construct. The purpose of this biomechanical study was to analyze the effect of this modification for the fixation of GT fractures.

Materials and methods

Sixteen fresh-frozen human cadaveric shoulders were used in this study. The fracture models were arbitrarily assigned to one of two fixation methods. Group A (n = 8) was fixed with two threaded cancellous screws with washers. In group B (n = 8), all screws were set using methods identical to group A, with the addition of a cerclage wire. Horizontal traction was applied via a stainless steel cable fixed directly to the myotendinous junction of the supraspinatus muscle. Displacement of the fracture fixation under a pulling force of 100 N/200 N and loading force to construct failure were measured.

Results

The mean displacements under 100 N and 200 N traction force were both significantly decreased in group B than in group A. (100 N: 1.06 ± 0.12 mm vs. 2.26 ± 0.24 mm, p < 0.001; 200 N: 2.21 ± 0.25 mm vs. 4.94 ± 0.30 mm, p < 0.001) Moreover, the failure load was significantly higher in group B compared with group A. (415 ± 52 N vs.335 ± 47 N, p = 0.01),

Conclusions

The current biomechanical cadaveric study demonstrated that the two-screw fixation construct augmented with a cerclage wire has higher mechanical performance than the conventional two-screw configuration for the fixation of humeral GT fractures.

Trial registration

Retrospectively registered.

Late screw-related complications in locking plating of proximal humerus fractures: A systematic review

Locking plating is a common surgical treatment of proximal humeral fractures with satisfactory clinical results. Implant-related complications, especially screw-related, have been reported, however, the lack of information regarding their onset, used surgical technique, complexity of the fracture, bone quality etc., prevents from understanding the causes for them. The aim of this systematic review is to identify the potential risk factors for late screw complications by gathering information about the patient characteristics, comorbidities, fracture types, surgical approaches and implant types. A PubMed search was performed using humerus, fractures, bone and locking as keywords in clinical papers written in English. All abstracts and manuscripts on distal or humerus shaft fractures, and those on proximal humerus fractures without any or with only iatrogenic complications were excluded. One hundred studies met the inclusion criteria, resulting in 33% of the reported cases having at least one complication, with 11% of all complications being screw-related. Most of the latter were secondary screw perforations and screw cut-outs, being predominantly linked to poor bone quality, while screw loosening and retraction were found less frequently as a result of locking mechanism failure. Overall, the amount of information for complications was limited and screw perforation was the most frequent screw-related complication, mostly reported in female patients older than 50 years, following four-part or AO/OTA type C fractures and detected four weeks postoperatively. The sparse information in the literature could be an indicator that the late screw complications might have been under-reported and under-described, making the understanding of the screw-related complications even more challenging.

Missed fractures of the greater tuberosity

Background

Fractures of the greater tuberosity may result from a variety of mechanisms. Missed injury remains a persistent problem, both from a clinical and medico-legal point-of-view. Few studies on this topic are available in the literature. We present the clinical and radiological findings of a consecutive series of 17 patients who were diagnosed and managed with undisplaced greater tuberosity fractures.

Methods

A retrospective study of a consecutive series of 17 patients who sustained an occult greater tuberosity fracture were performed. Patients sustained a traumatic occult greater tuberosity fracture, underwent shoulder radiographs after trauma in 5 days and they were diagnosed as negative by a consultant radiologist. All patients received a standard assessment using MRI (Magnetic Resonance Imaging) scans Each patient was evaluated for arm dominance, trauma history, duration and type of symptoms and post-treatment Oxford Shoulder Score.

Results

At the final follow up the mean OSS (Oxford Shoulder Score) was 38.3 (range 17–46; SD 9.11). Three patients required a glenohumeral joint injection for post-traumatic pain and stiffness and three patients required subacromial decompression for post-traumatic impingement.

Conclusions

Though undisplaced greater tuberosity fracture can be managed non-operatively with good results, patients with persistent post-traumatic shoulder pain, tenderness and limitation of shoulder function warrant investigation with MRI to identify occult fractures. Prompt identification of these fractures can facilitate patient treatment and counselling, avoiding a source of patient dissatisfaction and litigation.