Effect of a Variable Prosthetic Neck-Shaft Angle and the Surgical Technique on Replication of Normal Humeral Anatomy

Jinyoung Jeong; Bryan, Jason; Iannotti, Joseph P.
August 2009
Journal of Bone & Joint Surgery, American Volume;Aug2009, Vol. 91-A Issue 8, p1932
Academic Journal
Background: Replicating the normal anatomy of the shoulder is an important principle in the design of prosthetic devices and the development of surgical techniques. In this study, we used a three-dimensional surgical simulation to compare the abilities of an adjustable neck-shaft angle prosthesis and a fixed neck-shaft angle prosthesis to restore the normal geometry of the proximal part of the humerus. Methods: A total of 2058 cadaveric humeri were measured to define the normal distribution of neck-shaft angles. Thirty-six humeri were selected to represent a wide variation in neck-shaft angles, and computed tomographic scans with three-dimensional reconstruction were made of these specimens. With use of a three-dimensional computer surgical simulator, the humeral head was then cut at the anatomic neck to replicate a normal neck-shaft angle and version or it was cut at a fixed 135° angle with anatomic version. The anatomy of an adjustable-angle prosthesis and that of a fixed- angle prosthesis of the same design were both compared with native humeral anatomy in three dimensions. Results: The average neck-shaft angle of the 2058 humeri was 134. 7° (range, 115° to 148°), and the angle was between 130° and 140° in 77.84% of the humeri. In the setting of a high varus or valgus neck-shaft angle, an adjustable-angle prosthesis allowed optimal reconstruction when the humeral head was cut along the anatomic neck and allowed a standard and consistent surgical technique with use of anatomic landmarks. A fixed-angle prosthesis also replicated the anatomic center of rotation, tuberosity-head height, and head volume if the surgical procedure was altered to adapt to variations in humeral anatomy. There was no significant difference in anatomic parameters between the two types of prostheses, except that in all cases the head thickness was decreased when a fixed-135°-angle prosthesis was used in a humerus with a high valgus or high varus neck-shaft angle, resulting in a smaller articular arc and percent articular surface match. Conclusions: This study demonstrates the ability of both an adjustable and a fixed neck-shaft angle prosthesis to replicate humeral anatomy. However, the fixed-angle device requires specific modifications of the surgical technique to accommodate the specific prosthetic design and optimize the surgeon's ability to replicate normal anatomic parameters in humeri with an extreme neck-shaft angle. Clinical Relevance: This information can be used to optimize humeral component placement intraoperatively.


Related Articles

  • THE PROSTHESIS--OR DELAYED FITTING? Friedmann, Lawrence W. // Angiology;Oct1972, Vol. 23 Issue 9, p518 

    Reports on the appropriate processes to be imposed on amputation, prosthetic fitting and training. Need to reconstruct the limb and provision of aids and training to reintegrate the patient into society; Purposes in the implementation of amputation; Aspects of prosthetic fitting technique.

  • Prosthetic replacement of shoulder joint: preliminary communication. Kessel, Lipmann; Bayley, Ian // Journal of the Royal Society of Medicine;Oct1979, Vol. 72 Issue 10, p748 

    The article reports on the result of the study on the prosthetic replacement of shoulder joint. Using a reversed semi-captive prosthesis, 24 total replacements of the shoulder have been carried out over a 5-year period. 13 shoulders were classified as good or very good whilst five shoulders were...

  • Skeletal scintigraphic appearance of an auto-transplanted osteoarticular plug: epiphyseal transplant. Morrison, Stuart C.; Makley, John T.; O'Donnell, James // Pediatric Radiology;Jul2003, Vol. 33 Issue 7, p482 

    Nuclear medicine bone scan is an essential diagnostic imaging tool both for the diagnosis and staging of bone tumors and in the follow-up of these patients. It is very important that we be able to discriminate between normal variants, changes related to altered physical stress, and recurrent...

  • Modulare Tumorprothesen des Humerus. Funovics, P. T.; Dominkus, M. // Der Orthopäde;Oct2010, Vol. 39 Issue 10, p968 

    The humerus is a common location of musculoskeletal tumors. Modular prostheses of the humerus, besides APC and biological reconstructions, allow restoration of resulting bone defects. The functional outcome is determined by the extent of bone and soft tissue loss. Anatomical shoulder prostheses...

  • The Reverse Total Shoulder Prosthesis. Rockwood Jr., Charles A. // Journal of Bone & Joint Surgery, American Volume;Feb2007, Vol. 89-A Issue 2, p233 

    The article discusses a report presented in this issue of the periodical entitled "The Use of the Reverse Shoulder Prosthesis for the Treatment of Failed Hemiarthroplasty for Proximal Humeral Fracture." The author cites several insights and informations relating to the said article, including...

  • The Use of the Reverse Shoulder Prosthesis for the Treatment of Failed Hemiarthroplasty for Proximal Humeral Fracture. Levy, Jonathan; Frankle, Mark; Mighell, Mark; Pupello, Derek // Journal of Bone & Joint Surgery, American Volume;Feb2007, Vol. 89-A Issue 2, p292 

    Background: Humeral hemiarthroplasty is an established treatment for patients with selected fractures of the proximal part of the humerus. However, a subset of patients have development of glenoid arthritis and rotator cuff deficiency due to tuberosity failure. To date, there has been no...

  • Limb sparing surgery for bone tumours of the shoulder girdle: the oncological and functional results. Yang, Qiang; Li, Jianmin; Yang, Zhiping; Li, Xin; Li, Zhenfeng // International Orthopaedics;Aug2010, Vol. 34 Issue 6, p869 

    It is a great challenge to spare the upper limb with a malignant or invasive benign bone tumour of the shoulder girdle. We retrospectively analysed 35 patients with bone tumours of the shoulder girdle treated with various limb salvage procedures. The tumours included 25 primary malignancies,...

  • Specific treatments particularly suited to minimally invasive procedures. Meszaros, Liz // Cosmetic Surgery Times;Jun2003, Vol. 6 Issue 5, p15 

    Discusses how minimal-incision procedure techniques have made several standard approaches to cosmetic surgery. Inclusion of a small submental incision from which the platysma muscle can be tightened; Use of a preauricular incision for face lifting procedures.

  • Plastic surgery: a specialty on its knees. Davis, D.M. // British Medical Journal (Clinical Research Edition);12/12/1987, Vol. 295 Issue 6612, p1502 

    Reports the offering of plastic surgery services in the National Health Service in Great Britain. Increase in demand for plastic surgery; Introduction of surgical techniques; Reasons for the shortage of plastic surgeons.


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics