Radiological and biomechanical assessment of displaced greater tuberosity fractures

F, Meisterhans M, Borbas P, Wieser K, Grubhofer F. Anterior shoulder dislocation with avulsion fracture of the greater tuberosity results in reliable good outcomes after closed reduction

Background

Avulsion of the greater tuberosity (GT) due to traumatic anterior shoulder dislocation (ASD) is a commonly observed fracture pattern. After closed reduction of the dislocated humerus, the GT typically reduces itself into its anatomic position enabling the patient to undergo conservative treatment. The aim of this study was to retrospectively review a consecutive series of patients with conservatively treated GT avulsion fractures after closed reduction of an ASD and analyze radiographic outcome, shoulder function and glenohumeral stability and the conversion rate to surgical treatment.

Methods

All patients who underwent closed reduction of a GT avulsion fracture after ASD with the primary intention of conservative treatment between 2017 and 2022 were included. Complications (i.e. conversion to surgical treatment), shoulder function assessed with the American Shoulder and Elbow Surgeons score and subjective shoulder value, instability assessed with the Western Ontario Shoulder Instability score, radiological impingement (greater tuberosity index = GTI and impingement index = II) and GT fracture pattern were assessed as outcome measurements.

Results

A total of 29 patients (mean age 44 years, 27% female) with a mean follow-up of 32.6 (range, 8-96) months were enrolled. Seven patients (24%) underwent surgery due to secondary displacement (n = 4, 14%) or impingement symptoms (n = 3, 10%). All patients who underwent secondary surgery showed a multifragmentary fracture pattern of the GT. Shoulder stiffness (n = 7) and neuropraxia of the axillary nerve (n = 3) were observed temporarily and resolved during the follow-up period. The American Shoulder and Elbow Surgeons and subjective shoulder value of the conservatively treated patients at the last follow-up was 89.2 ± 19.1 respectively 86 ± 18.2%. No recurrent glenohumeral dislocation was documented. The mean Western Ontario Shoulder Instability score at last follow-up was 8(0-71). The mean GTI decreased from 1.2 ± 0.1 after ASD to 1.1 ± 0.1 at the last follow-up (P = .002). The mean II decreased from 0.6 ± 0.5 after ASD to 0.4 ± 0.3 at the last follow-up (P = .110).

Conclusion

The GT avulsion fragment reduces typically into a close to anatomic position after closed reduction and the GTI even improves with further conservative treatment over time. Close radiological follow-up is necessary to rule out secondary displacement which occurs typically in a multifragmentary fracture pattern. Patients without the need for surgery showed good clinical outcomes without recurrence of glenohumeral instability.

Radiological analysis and outcomes of isolated greater tuberosity fracture-dislocations

BACKGROUND

The purpose of this study was to investigate different radiological characteristics for isolated greater tuberosity (GT) fracture-dislocations and their effects on complication and reoperation rates.

METHODS

A two-centre, retrospective study was performed on patients with a minimum 1-year follow-up (median 4.5 years). Patients were split into two groups, Group A (<65 years old) and Group B (≥65 years old). Outcomes included initial injury characteristics (dislocation and fracture type, AC/BC ratio and distances), the reduction environment and postreduction outcomes including complications.

RESULTS

A total of 55 patients were included in this study, with a reduction in the emergency department (ED) performed in 93% of patients. Complication rates (47% overall) were similar in both groups, with an overall nonunion rate of 27%. No nonunions occurred in fractures reduced in theatre compared with 29% occurring in reductions in ED (p<0.001); 11% of patients experienced surgical neck fractures, the majority of which were in Group B (p=0.003). A larger fracture fragment (i.e. higher AC/BC or AC distances) was correlated with a higher incidence of nonunion in Group B compared with Group A (p=0.003), and a higher risk of stiffness in both groups (p=0.049); 16% of patients demonstrated delayed displacement of their GT.

CONCLUSIONS

This study highlights the high complication rates associated with these injuries. Age and specific radiological parameters should be taken into consideration when risk stratifying, as should reducing these fractures in a theatre setting. Interval radiographs are also advised to monitor GT displacement for at least 2-3 weeks.

How to treat stiffness after proximal humeral fractures?

Shoulder stiffness is a frequent complication after proximal humeral fractures treated with or without surgery. Shoulder stiffness is associated with high rates of absence from work and a significant financial burden for the healthcare system. Secondary stiffness is characterized by additional extracapsular adhesions, including subacromial, subcoracoid, and subdeltoid spaces, usually derived from post-fracture or post-surgical extraarticular hematomas. Several secondary causes may coexist with capsular and extracapsular adhesions decreasing the shoulder motion, such as malunion, nonunion, metalwork failure, infection, and osteoarthritis, among others. Conservative treatment, usually prescribed for primary shoulder stiffness, has shown unfavorable results in secondary stiffness, and surgical intervention may be required. Surgical interventions need to be patient-specific. Usually, open or arthroscopic fibro-arthrolysis and subacromial release are performed, together with plate removal and biceps tenotomy/tenodesis. In severe osteoarthritis, shoulder replacement may be indicated. Ruling out infection is recommended in every case.

Greater Tuberosity Fractures after RTSA: A Matched Group Analysis

Periprosthetic fractures, such as acromial and spine fractures, are known complications following implantation of reverse shoulder arthroplasty (RTSA). The entity of greater tuberosity fractures (GTF) has rarely been studied in the literature. The purpose of this study was to analyze the outcome of postoperative greater tuberosity fractures after RTSA compared to a matched control group. The main findings of this study are that a GTF after RTSA is associated with worse clinical outcome scores (mean absolute CS 50 ± 19 (p = 0.032); SSV 63% ± 26 (p = 0.022); mean force 1 kg ± 2 kg (p = 0.044)) compared with the control group (mean absolute CS 62 ± 21; SSV 77% ± 29; mean force 2 kg ± 2 kg). In terms of postoperative range of motion, the fracture group was significantly worse in terms of external rotation (17° ± 19° vs. 30° ± 19° (p = 0.029)). Internal rotation, flexion, as well as abduction of the shoulder appear to be unaffected (internal rotation GTF 4 ± 2, control group 5 ± 3 (p = 0.138); flexion GTF 102° ± 28°, control group 114° ± 27° (p = 0.160); abduction GTF 109° ± 42°, control group 120° ± 39° (p = 0.317)).

Midterm results of pyrocarbon interposition shoulder arthroplasty: good outcomes after posttraumatic osteonecrosis without malunion of the tuberosities

Background

In vitro data demonstrate the potential benefits of the pyrocarbon as a bearing material against cartilage or bone. And pyrocarbon-free interposition arthroplasty has been used with positive outcomes for over 10 years for hand and wrist joint replacements. This study reports the midterm results of a Pyrocarbon Interposition Shoulder Arthroplasty (PISA) in primary and secondary glenohumeral osteoarthritis and in avascular osteonecrosis.

Methods

This prospective noncontrolled, multicenter study included 67 consecutive patients who underwent PISA in France and Sweden.

Results

A cohort of 48 patients, aged 50 ± 12 years, was available for clinical assessment at a mean follow-up of 67.6 ± 9.3 months. A favorable change was reported with a mean absolute Constant score improvement of 32 ± 20 points. The highest Constant score improvement was observed in patients with avascular osteonecrosis (42 ± 18 points; P ≤ .0001). Between the earliest and the latest follow-up, radiographic analyses revealed only 2 major glenoid erosions and 4 tuberosity thinnings and thus that 86.4% of 44 shoulders remained stable with no or minor radiologic evolutions. The survival rate was 84 % at 65 months of follow-up considering all causes of revision.

Conclusion

The radiographic findings seem to confirm the interest of pyrocarbon in preserving bony surfaces. But the risk of tuberosity thinning suggests considering the use of PISA with caution in most degenerative glenohumeral joint pathologies, although the midterm outcomes highlight PISA as a suitable solution for patients presenting with posttraumatic osteonecrosis without malunion of the tuberosities and with an intact rotator cuff.

Avaliação funcional do ombro após osteossíntese da fratura da tuberosidade maior: Há influência da luxação glenoumeral?

Objetivo Avaliar os resultados funcional e radiográfico pós-operatórios do ombro, em pacientes submetidos a sutura transóssea de fratura da tuberosidade maior (FTM) por acesso anterolateral, e a influência da luxação glenoumeral nesses resultados.

Métodos Realizou-se estudo retrospectivo e avaliação funcional (pela escala de Constant-Murley). Calculou-se a distância entre a tuberosidade maior e a superfície articular do úmero proximal (por meio de radiografia em incidência anteroposterior verdadeira) após a consolidação. Usou-se o teste Exato de Fisher para as variáveis independentes categóricas, e os testes tde Student ou de Mann-Whitney para as não categóricas.

Resultados Ao todo, 26 pacientes preencheram os critérios de inclusão. A associação de luxação glenoumeral com FTM foi observada em 38% da amostra. A média da pontuação na escala de Constant-Murley foi de 82,5 + 8,02. A presença de luxação associada não alterou o resultado funcional. A distância média da consolidação da tuberosidade maior do úmero em relação à superfície articular da cabeça umeral foi de 9 + 4,3 mm abaixo da linha articular da cabeça umeral. Pacientes com luxação associada evoluíram com redução menor, mas isso não influenciou na pontuação na escala de Constant-Murley.

Conclusão As FTMs submetidas ao tratamento cirúrgico com sutura transóssea evoluíram com bom resultado funcional. A presença de luxação dificultou a redução anatômica da tuberosidade maior. Entretanto, isso não influenciou na pontuação na escala de Constant-Murley.

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.

Hinge plate technique for osteosynthesis of comminuted proximal humeral fractures

BACKGROUND

Several surgical techniques of osteosynthesis have been described for treatment of proximal humeral fractures. There is evidence that the quality of reduction improves the clinical outcome and decreases the number of complications. Reduction of the medial calcar is tricky when standard manoeuvres are performed. We have therefore augmented our standard surgical technique with a low-profile medial hinge plate which aims at better reconstructing the medial metaphysis without extensile soft tissue dissection in combination with proximal humerus locked plating.

OBJECTIVE

Evaluate the radiological and clinical outcome after application of an augmented fixation with a low-profile medial hinge plate. We questioned: (i) The quality of reduction, (ii) The rate of complications, (iii) The clinical function in terms of the Oxford Shoulder Score (OSS).

METHODS

A retrospective single-centre case series. Between 2016 and 2019, patients who had undergone open reduction and osteosynthesis by an anatomical locking plate associated with a 2.0 mm locking compression plate used as a hinge to support the medial metaphysis. Thirty-four patients, with an average age of 64 years had a clinical and/or radiological average follow-up of 36 months.

RESULTS

The preoperative imaging identified three fractures in two parts, 19 fractures in three parts and 12 fractures in four parts. Seven cases with fracture-dislocation were identified, one head-split fracture, and 14 cases with a metaphyseal head extension of less than 8 mm. After comparing head-shaft displacement, cranialisation of the greater tuberosity as well as head-shaft alignment in the preoperative and postoperative radiographs, overall anatomical or near-anatomical fracture reduction was achieved in 27 of the patients. Only two cases presented postoperative complications. The two cases were complicated with nonunion without screw perforation requiring surgical intervention by re-osteosynthesis. The clinical outcome assessed by the OSS showed an average of 45/48. The age of the group with anatomical or near anatomical reduction and the group with at least one parameter of malreduction was significantly different, 65 and 74 years respectively (p<0.05). No significant differences were found when comparing the sex, surgical time, time to operation or the number of fracture parts.

CONCLUSION

The technique described provides a surgical treatment option with lower complication rates and a quality of reduction consistent with the current literature as well as a satisfactory clinical outcome.