The Benefits of Preserving the Coracoid Process and Its Attachments

This article refers to:

Feasibility Analysis and Clinical Applicability of a Modified Type V Resection Method for Malignant Bone Tumors of the Proximal Humerus

The shoulder girdle consists of the scapula, proximal humerus, 1/3 lateral clavicle, and soft tissue attachments. The proximal humerus is the most common site for malignant tumors in the shoulder girdle [1, 2], and chondrosarcoma and osteosarcoma are common types of tumor. The functional components around the proximal humerus are comprised of the deltoid, brachialis, remaining rotator cuff musculature, latissimus dorsi, subscapularis, and parts of the triceps. The characteristics of this area make it very difficult for surgeons to excise the tumors while attempting to maintain the maximum function and appearance of the shoulder joint. For the treatment of malignant tumors in the proximal humerus, upper limb amputation has been replaced with limb sparing surgery at present. Clinicians perform tumor excision surgery prior to performing artificial prosthesis replacement surgery. Hence, patients must undergo a surgery before carrying on with the functional anatomic reconstruction procedures. After going through this process, patients could experience an increase in quality of life with less psychological burden as a result of preserved shoulder joint function and an intact upper limb contour.

In 1991, Malawer demonstrated his creativity by proposing a six-stage surgical classification system that categorizes shoulder girdle resections from type I to type VI [3]. Generally speaking, patients with a low-grade tumor in the shoulder girdle are classified from type I to type III, whereas patients with high-grade malignant tumors are classified from type IV to type VI. This sort of system is based on the current concepts associated with surgical margins, the relationship of the tumor with the anatomic compartments (i.e., intracompartmental vs. extracompartmental), the status of the glenohumeral joint (intraarticularvs. extraarticular), the magnitude of the individual surgical procedures, and the presence or absence of the abductor mechanism (deltoid muscle, rotator cuff muscle, or both) [4]. Traditionally, the resection for type V involves the extraarticular humeral and glenoid region inside the coracoid. This surgery has the potential to result in defective bones or tissues including but not limited to the coracoid process, acromion, and glenoid fossa. To avoid this, the author of the article presented a modified type V resection without the need for excising the acromion, clavicle, and coracoid process. The image presented in the article showed that the lesions of the recruited participants invaded the scapula glenoid fossa but not the acromion or coracoid through preoperative examinations. Notably, all of the patients' tumor invasion sites were localized at S1.⁵ The authors of the study took indexes of SC, GC, and AC [6] and calculated the horizontal distance between the maximum longitudinal diameter and the basal outside lateral margin of the coracoid process using a trigonometric functional relationship. The results revealed that no surgical damage was inflicted in the coracoid process during and after resection of the shoulder joint capsule. The actual surgical procedure proved the applicability and validity of the theoretical analysis. At the end of the surgery, the surgeons retained the coracoacromial ligament and reconstructed the coracoclavicular ligament, the acromioclavicular joint, and the surrounding soft tissues by using an artificial mesh patch, at which time they also reattached the coracobrachialis and short head of the biceps brachii to the coracoid process. The results showed that shoulder joint function was significantly improved compared with preoperative or conventional Type V resection [7]. What should not be ignored is that one of the participants had experienced local recurrence and underwent upper limb amputation.

The current study provides an innovative surgical option for the resection of malignant bone tumors of the proximal humerus. The results are enlightening, as this study reawakens our awareness of the function of the coracoid process and its surrounding attachments. Previous studies often focused on achieving extensive resection to prevent tumor recurrence in most cases. This is understandable, as the medical techniques and equipment were insufficient and the structure of the shoulder joint was not thoroughly studied at that time. Functional rehabilitation was also considered less important than patient survival. Yet now, with improvements in examination techniques, patients have higher demands for postoperative recovery and quality of life. Less tissue damage within a reasonable resection range often means faster and better recovery. We surgeons should change our mindset and adopt new techniques to meet the requirements.

On the other hand, we must acknowledge the following deficiencies of the aforementioned study: a short-term follow-up time; a non-randomized, controlled clinical trial; and a small sample size. In the future, higher quality, randomized, controlled studies with long-term follow-up and large sample sizes should be conducted to confirm the reliability and authenticity of the modified surgical procedure.

Declaration of interest

The author reports no conflicts of interest. The author alone is responsible for the content and writing of the article.