Purpose of the study: With the advent of angle-stable implant systems in surgical treatment of proximal humeral fractures, the number of indications to shoulder hemiarthroplasty decreased dramatically, because these modern implants provide certain fixation of osteoporotic bone fragments in elderly patients.
Material and methods: The authors report on their experience with shoulder replacement surgery in 29 patients, of which 26 underwent urgent surgery. The indications for acute hemiarthroplasty included humeral head fractures in which destruction of the articular surface exceeded 40 %, and fractures with evident or suspected insufficient vitality of the humeral head in elderly patients. Other indications included intra-operative osteosynthesis with the necessity of subsequent intra-operative conversion. Two patients with late implant failure and one with bone malunion, after conservative treatment of a fracture, were indicated for second stage hemiarthroplasty. The authors draw attention to the most frequent errors associated with this surgery and describe guidelines used in post-operative care. A total of 20 patients were evaluated by the Constant Score at an average follow-up of 12.5 months (range, 6-39 months).
Results: Shortly after the operation, loosening of parts of the modular prosthetic system occurred in two patients. Aseptic loosening of the stem was observed in two patients, and early deep wound infection was found in two patients. The implant was removed in two cases, once for its loosening, and once for persisting infection. None of the patients died due to causes related to shoulder hemiarthroplasty. The functional outcomes corresponded to the choice of patients, because the indications for hemiarthroplasty involved the most serious fractures in elderly patients. Post-operative subjective evaluation usually showed only intermittent and mild pain; only four patients complained of severe pain. Arm elevation in the youngest age group, i.e., up to 59 years, was 100 degrees on the average, with a range of 70 to 140 degrees. In the patients 60 to 69 years old, the average elevation was 95 degrees, with a range of 90 to 110 degrees; in the oldest group, i.e., 70 years and older, the average elevation was 75 degrees and the range was 30 to 130 degrees. Excellent outcomes with elevation over 120 degrees were achieved in four patients only. The average Constant Scores in the three age groups were 68, 54 and 42 points, respectively.
Discussion: When deciding the indications for hemiarthroplasty, many factors must be considered. Beside the type of fracture and patient's age, a possible impairment of blood supply, which is associated with avascular bone necrosis, must also be taken into account. Criteria for correlation between vascularisation impairment and X-ray findings, with the analysis of advantages and disadvantages of hemiarthroplasty, are described in this article. In the end, an indication scheme for the treatment of proximal humeral fractures is suggested.
Conclusions: Good results achieved in shoulder hemiarthroplasty are related to both the development of modular prosthetic systems for shoulder replacement and a faultless surgery procedure itself. Careful and long-term post-operative care also plays an important role. Functional outcomes after acute hemiarthroplasty are clearly better than those after a second-stage operation performed when conservative treatment or previous osteosynthesis have failed.