Reconstructing proximal humeral fractures using the bicipital groove as a landmark

Automatic bicipital groove identification in arthritic humeri for preoperative planning: A Random Forest Classifier approach

The bicipital groove is an important anatomical feature of the proximal humerus that needs to be identified during surgical planning for procedures such as shoulder arthroplasty and proximal humeral fracture reconstruction. Current algorithms for automatic identification prove ineffective in arthritic humeri due to the presence of osteophytes, reducing their usefulness for total shoulder arthroplasty. Our methodology involves the use of a Random Forest Classifier (RFC) to automatically detect the bicipital groove on segmented computed tomography scans of humeri. We evaluated our model on two distinct test datasets: one comprising non-arthritic humeri and another with arthritic humeri characterized by significant osteophytes. Our model detected the bicipital groove with a mean absolute error of less than 1mm on arthritic humeri, demonstrating a significant improvement over the previous gold standard approach. Successful identification of the bicipital groove with a high degree of accuracy even in arthritic humeri was accomplished. This model is open source and included in the python package shoulder.

Clinical relevance of the anatomy of the long head bicipital groove, an evidence-based review

Pathology in the bicipital groove can be a source of anterior shoulder pain. Many studies have compared treatment techniques for the long head biceps tendon (LHBT) without showing any clinically significant differences. As the LHBT is closely related to the bicipital groove, anatomical aspects of this groove could also be implicated in surgical outcomes. The aim of this review is to contribute to developing the optimal surgical treatment of LHBT pathology based on clinically relevant aspects of the bicipital groove. Medline/PubMed was systematically searched using key words "bicipital" and "groove" and combinations of their synonyms. Studies reporting on evolution, embryonic development, morphometry, vascularization, innervation, and surgical treatment of the LHBT and the bicipital groove were included. The length of the bicipital groove reported in the included studies ranged from 81.00 mm to 87.33 mm, width from 7.74 mm to 11.60 mm, and depth from 3.70 mm to 6.00 mm. The anatomy of the bicipital groove shows a bottleneck narrowing approximately two-thirds from superior. The transverse humeral ligament can constrain the bicipital groove and could be involved in anterior shoulder pain. When either LHBT tenotomy or tenodesis is performed, routinely releasing the transverse ligament could decrease postoperative anterior shoulder pain, which has frequently been reported in the literature. To avoid the bottle neck narrowing, a location below the bicipital groove may be preferred for biceps tenodesis over a more proximal tenodesis site. Level of evidence: IV.

The bicipital groove as a landmark for reconstruction of complex proximal humeral fractures with hybrid double plate osteosynthesis

Background

Complex proximal humerus fractures with metaphyseal comminution remain challenging regarding reduction and stability. In most fracture patterns the hard bone of the bicipital groove remains intact. In this case series, we describe a novel technique of hybrid double plate osteosynthesis of complex proximal humerus fractures with metaphyseal comminution.

Methods

In randomly chosen shoulder specimens and synthetic bones, pilot studies for evaluation of the feasibility of the technique were performed. Between 4/2010 and 1/2012 10 patients underwent hybrid double plate osteosynthesis. Seven patients (4 male, 3 female, mean age was 50 years (range 27–73)) were available for retrospective analysis. Based on plain radiographs (anterior-posterior and axial view), the fractures were classified according to the Orthopaedic Trauma Association classification (OTA) and by descriptive means (head-split variant (HS), diaphyseal extension or comminution (DE)).

Results

Follow-up radiographs demonstrated complete fracture healing in six patients and one incomplete avascular necrosis. None of the patients sustained loss of reduction. Three patients where reoperated. The medium, not adapted, Constant score was 80 Points (58–94). Patients subjective satisfaction was graded mean 3 (range: 0–6) in the visual analog scoring system (VAS).

Conclusion

The technique of hybrid double plate osteosynthesis using the bicipital groove as anatomic landmark may re-establish shoulder function after complex proximal humerus fractures in two dimensions. Firstly the anatomy is restored due to a proper reduction based on intraoperative landmarks. Secondly additional support by the second plate may provide a higher stability in complex fractures with metaphyseal comminution.

Radiographic landmark for humeral head rotation: a new radiographic landmark for humeral fracture fixation

BACKGROUND

There is no definite radiographic landmark in plain radiographs for proximal humeral rotation, which is an important parameter for avoiding rotational malalignment during fracture fixation. Here, we used radiographic images of cadaveric humeri to determine whether the landmark of the crest of lesser tuberosity (CoLT) in plain radiographs could be used to determine humeral rotation.

METHODS

Twenty adult cadaveric humeri were collected and seven consecutive radiographic anteroposterior views (45°, 30°, 15° internal rotation; neutral rotation; and 15°, 30°, 45° external rotation) were obtained for each specimen.

RESULTS

The proportional distance (PD) of the CoLT landmark relative to the humeral head was measured and analysed. The mean PDs of the CoLT landmark were 10.2%, 17.9%, 25.6%, 35.9%, 53.4%, and 62.9% of the diameter of the humeral head, corresponding to 45°, 30°, and 15° external rotation, neutral rotation, and 15° and 30° internal rotation, respectively. We found significant differences in the mean PDs with humeral rotation.

CONCLUSION

The projection of the CoLT in plain radiographs can be used as an important landmark to assess humeral head rotation and will be a useful landmark for rotational control of fracture fixation.

Repositioning of the humeral tuberosities can be guided by pectoralis major insertion

In complex proximal humerus fractures, positioning of the tuberosities can be a challenge. This study demonstrates the constant angle between the pectoralis major (PM) and the medial lip of the bicipital groove (BG) on the horizontal axial plane. This angle can be used to determine the rotation, as well as the positioning of the tuberosities, when planning a hemiarthroplasty or a reconstruction. Thirty-one shoulder MRIs were reviewed by three independent observers. The measurements were taken by superposing the axial cut of the proximal humerus, at the level of the distal bicipital groove, and the cut at the top of the PM insertion. By aligning the centers of rotation, we could determine the arcs of rotation between the insertion of the PM and the lips of the medial and lateral bicipital groove (MBG and LBG). Both angles were compared in terms of reliability, reproducibility, and precision. The mean PM-MBG angle was 3.7° [standard deviation (SD) 14.7°] and 27.4° (SD 14.4°) for the PM-LBG angle. We obtained good and very good intra-class correlation coefficient (ICC) results for inter- (0.675) and intra-observer (0.793) reliabilities on the medial angle, plus excellent results for the lateral angle (inter-observers 0.962 and intra-observer 0.895). This study demonstrates that the repositioning of humeral tuberosities can be guided by pectoralis major insertion. This will help achieve proper positioning of the metaphysis in relation to the diaphysis during surgery for complex proximal humerus fractures.

Metaversion can reliably predict humeral head version: a computed tomography-based validation study

HYPOTHESIS

Circumstances occur when the determination of anatomic humeral head version is difficult. In the setting of irreparable proximal humeral fracture, there are few reliable intraoperative landmarks to determine anatomic humeral head version. This study tested our hypothesis that the metaphyseal version (metaversion) is a landmark that can assist with correct head version and used computed tomography (CT) to evaluate its reliability as a predictor of anatomic version.

MATERIALS AND METHODS

CT scans from 50 consecutive patients (20 women, 30 men) were examined using commercial software. Patients were a mean age of 46 years (range, 17-85 years). Exclusion criteria included previous fracture, arthritis, or humeral deformity. The metaversion and humeral head version were measured. Measurements were conducted independently by 2 surgeons blinded to the results of the other. Interobserver and intraobserver reliability was calculated using intraclass correlation.

RESULTS

The mean difference between the metaversion and the humeral head version was 2.5° (95% confidence interval [CI], 0.9°-3.9°). The mean difference between metaversion and humeral head version was 1.8° (95% CI, 0.0°-3.6°) in women, 2.9° (95% CI, 0.6°-5.1°) in men, 2.4° (95% CI: 0.6°-4.1°) in right shoulders, and 2.5° (95% CI, -0.1° to 5.1°) in left shoulders. Interrater and intrarater reliability was excellent, 0.97 and 0.98, respectively.

CONCLUSIONS

Proximal humeral metaphyseal version (metaversion) is an accurate predictor of ipsilateral humeral head version.

Shoulder arthroplasty for acute proximal humerus fracture

Proximal humerus fracture devascularizing the humeral head may require management by prosthesis. Hemiarthroplasty is a logical attitude in such cases, but analysis of functional results and complications has identified a certain number of risk factors limiting indications. Strict analysis of patient characteristics and of fracture type is an essential prerequisite to deciding against treatment by immobilization or osteosynthesis. Results in hemiarthroplasty are primarily dependent on respecting the rules of the art, which aim at stable anatomic osteosynthesis of the surrounding structures so as to restore normal shoulder function. The critical steps are the adjustment of implant height and retroversion, reduction and fixation of tuberosities and good management of the postoperative course. The recent development of fracture-dedicated shoulder implants should improve results. In elderly patients, when local conditions are unsuitable to hemiarthroplasty, a reverse prosthesis may be used, with an adapted surgical technique. Whatever the type of prosthesis, implantation for proximal humerus fracture is a demanding operation with definitive impact on the functional evolution of the shoulder.

Morphometry of the human bicipital groove (sulcus intertubercularis)

BACKGROUND

The bicipital groove is located between the greater and lesser tubercles at the proximal extremity of the humerus and extends inferiorly. Citations that anatomic variations of the groove could give rise to sliding of the biceps brachii muscle tendon led us to initiate a morphometric study on this groove.

MATERIALS AND METHODS

The study was done on 50 dry humeral bones from adults of both genders and from both sides. A digital caliper rule was used to measure the length, thickness and width of the bicipital groove and the humerus. The angles of the bicipital groove were measured with a goniometer.

RESULTS

The average length of the groove was 8.1 cm and it corresponded to 25.2% of the length of the humerus. The width at the midpoint of the groove was 10.1 mm and corresponded to 49.7% to 54.5% of the width of the humerus. The depth was 4.0 mm and corresponded to 18.8% of the depth of the humerus. The mean angle formed by the groove lips was 106 degrees .

CONCLUSION

This study confirmed the variability of the measurements presented by the groove in relation to all the aspects considered.

LEVEL OF EVIDENCE

Basic Science.

Attachments of muscles as landmarks for implantation of shoulder hemiarthoplasty in fractures

BACKGROUND

The attachments of muscles and the position of the humeral head are important for a good functional outcome of shoulder hemiarthroplasties after displaced fractures of the proximal humerus. Deviations in the attachments and changes in their spatial position with respect to the humeral head during surgical reconstruction change the biomechanics and reduce the range of motion of the should joint postoperatively.

METHODS AND RESULTS

We used 198 humerus preparations and using 3-dimensional analysis measured the angular relationships between the humeral head axis and medial margin of the greater tuberosity (11.9 degrees +/- 9.1 degrees ), lateral margin of the lesser tuberosity (48.0 degrees +/- 7.8 degrees ), and the crest of the greater tuberosity (27.1 degrees +/- 9.6 degrees ).

CONCLUSION

This study provides average values of the positions of the greater and lesser tuberosities with respect to the humeral head axis. We show that the greater and lesser tuberosities are more reliable than the transepicondylar line for reconstruction of humeral head retroversion.

LEVEL OF EVIDENCE

Basic Science.

Lesser tuberosity is more reliable than bicipital groove when determining orientation of humeral head in primary shoulder arthroplasty

PURPOSE

The objective of the study was to provide statistical evaluation of position of bone landmarks of proximal humerus in relation to transepicondylar line and find out which one is the most suitable for setup of the head retroversion in case of humeral head destruction.

METHODS

We measured 185 dry humeral preparations (92 left, 93 right). Structures of interest on the proximal humerus were marked with pointers of custom made steel frame. Angular relationships between the humeral head axis and medial margin of the greater tuberosity, lateral margin of the lesser tuberosity, bicipital groove, and crest of the greater tuberosity were evaluated with respect to intramedullary axis of the proximal humeral shaft.

RESULTS

The angle between the humeral head axis and medial margin of greater tuberosity was 11.5 +/- 9.0 degrees , the angle between the lateral margin of the lesser tuberosity and the axis was 47.5 +/- 7.4 degrees , the angle between the bicipital groove and the axis was 31.6 +/- 8.8 degrees at the level of the humeral head. The angle between the crest of the greater tuberosity and the axis was 26.6 +/- 9.6 degrees in plane of the surgical neck.

CONCLUSIONS

We statistically proved that the lateral margin of lesser tuberosity is more reliable than the bicipital groove; medial margin of the greater and transepicondylar line for reconstruction of humeral head retroversion. We suggest that the lesser tuberosity should be used to determine the retroversion, especially in cases when the margin of humeral head was destructed.