Mr Younghein and Drs Eskander, DeAngelis, and Wixted are from the Department of Orthopedic Surgery, University of Massachusetts Medical School, Worcester, Massachusetts.
Mr Younghein and Drs Eskander, DeAngelis, and Wixted have no relevant financial relationships to disclose.
Correspondence should be addressed to: John J. Wixted, MD, Department of Orthopedic Surgery, University of Massachusetts Medical School, 55 Lake Ave N, Worcester, MA 01655 (email@example.com).
Unicameral bone cysts are benign, fluid-filled, lytic lesions most commonly found in the long bones of skeletally immature children.1,2 In addition, a male predominance exists, ranging from 3:1 to 2:1, and approximately 94% of unicameral bone cysts exist in the proximal humerus and femur, with the humerus being 2 times more likely to be affected than the femur.2,3 Unicameral bone cysts are rarely found in adults, and when present are more common in the iliac, radius, and ribs.4
This article describes the complexities of treatment of a devastating proximal humerus fracture secondary to a unicameral bone cyst.
A 40-year-old woman presented with a proximal humerus fracture dislocation (Figure 1) after slipping on an icy train platform and landing on her right arm. She reported no relevant medical history and no history of musculoskeletal disease. Preoperative right shoulder plain radiographs and computed tomography scan (Figure 2) showed a 3-part head-splitting proximal humerus fracture dislocation through a large unicameral bone cyst. She was urgently reduced and held in a sling and swathe until she underwent surgery the next morning (Figure 3). Given the patient’s activity level and age, open reduction and internal fixation (ORIF) was performed to salvage the humeral head.
Figure 1: Anteroposterior (A) and axial (B) plain radiographs showing an unreduced 3-part head-splitting proximal humerus fracture with involvement of a unicameral bone cyst.
Figure 2: Prereduction computed tomography scan of the right proximal humerus fracture (A). Three-dimensional computed tomography reconstruction of the 3-part head-splitting humerus fracture (B).
Figure 3: Axial plain radiograph of the patient’s right shoulder after urgent closed reduction.
The patient underwent ORIF via the deltopectoral approach using a locking humeral plate, an interfragmentary screw, and two 4.0 cancellous screw fixations of the humeral head. The unicameral bone cyst was well corticated and allowed for humeral head reduction with a <1-mm stepoff. The unicameral bone cyst was packed with crushed cancellous bone and silicated calcium phosphate bone graft, and anteroposterior and lateral radiographs confirmed the filling of the cyst. Once the humeral plate was secured and the shoulder was anatomically reduced, the humerus was put through a full range of motion and was stable. Postoperative plain radiographs showed cortication of the cyst and acceptable humeral head reduction (Figure 4).
Figure 4: Anteroposterior (A) and axial (B) plain radiographs of the right shoulder after open reduction and internal fixation.
The patient was discharged on postoperative day 4 with no right shoulder or upper-extremity neurovascular deficit. The fracture healed well, but the patient reported continued stiffness and decreased range of motion following physical and occupational therapy. Approximately 1 year postoperatively, the patient underwent arthroscopy with manipulation, decompression, and lysis of the adhesions in her right shoulder with a satisfying improvement in symptoms (Figure 5).
Figure 5: Anteroposterior (A) and axial right shoulder radiographs approximately 1 year postoperatively showing approximately 1 mm of head reduction stepoff (B).
Multipart head-splitting fractures are devastating injuries, especially in young, active patients. The complexity of the current patient’s fracture care was increased because of the involvement of the unicameral bone cyst in the humeral head. Unicameral bone cysts usually form in the diaphysis and spread distally with bone growth. However, reports have been published of unicameral bone cysts with epiphyseal extension in an older age group, proposing the mechanism whereby juxtaphyseal cysts extend into the epiphyseal region after skeletal maturity.5–9 A literature review revealed no published reports of adult proximal humerus fractures associated with a previously undiagnosed, persistent unicameral bone cyst.
Multipart head-splitting proximal humerus fractures can result in a high incidence of avascular necrosis. They usually result from trauma in individuals this age.10,11 The current patient’s fracture can be described as a 3-part head-splitting fracture dislocation of the proximal humerus.11 In head-splitting fractures of the proximal humerus, hemiarthroplasty or arthroplasty are the preferred methods of repair to grant immediate mobilization without instability.11–14 Despite hemiarthroplasty being the gold standard, with the consideration of age, the current studies show 59% to 88% survival of hemiarthroplasty at 15 years, with lower survivals in patients with sequelae of trauma.15 Furthermore, almost half of all patients younger than 50 years who have undergone shoulder arthroplasty have reported an unsatisfactory result.15 In the current case, sparing the native bone was an acceptable alternative given the suboptimal long-term results of hemiarthroplasty. A plan was made for ORIF, and the option of a hemiarthroplasty or arthroplasty will still be available for an unsatisfactory result in this treatment sequence.16,17
This article describes the difficulties in treatment plan decision making for severe head-splitting fractures in the setting of a unicameral bone cyst in a young, active patient. Achieving successful reduction and vascular supply preservation to a head-splitting humerus fracture can be accomplished by performing ORIF while retaining acceptable shoulder joint range of motion.
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- Campanacci M, Capanna R, Picci P. Unicameral and aneurysmal bone cysts. Clin Orthop Relat Res. 1986; (204):25–36.
- Boseker EH, Bickel WH, Dahlin DC. A clinicopathologic study of simple unicameral bone cysts. Surg Gynecol Obstet. 1968; 127(3):550–560.
- Neer CS II, Francis KC, Marcove RC, Terz J, Carbonara PN. Treatment of unicameral bone cyst. A follow-up study of one hundred seventy-five cases. J Bone Joint Surg Am. 1966; 48(4):731–745.
- Gupta AK, Crawford AH. Solitary bone cyst with epiphyseal involvement: confirmation with magnetic resonance imaging. A case report and review of the literature. J Bone Joint Surg Am. 1996; 78(6):911–915.
- Haims AH, Desai P, Present D, Beltran J. Epiphyseal extension of a unicameral bone cyst. Skeletal Radiol. 1997; 26(1):51–54. doi:10.1007/s002560050191 [CrossRef]
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- Nelson JP, Foster RJ. Solitary bone cyst with epiphyseal involvement: a case report. Clin Orthop Relat Res. 1976; (118):147–150.
- Randelli P, Arrigoni P, Cabitza P, Denti M. Unicameral bone cyst of the humeral head: arthroscopic curettage and bone grafting. Orthopedics. 2009; 32(1):54 doi:10.3928/01477447-20090101-18 [CrossRef]
- Baron JA, Barrett JA, Karagas MR. The epidemiology of peripheral fractures. Bone. 1996; 18(3 suppl):209S–213S. doi:10.1016/8756-3282(95)00504-8 [CrossRef]
- Neer CS II, . Displaced proximal humeral fractures. Part I. Classification and evaluation. By Charles S. Neer, I, 1970. Clin Orthop Relat Res. 1987; (223):3–10.
- Ko JY, Yamamoto R. Surgical treatment of complex fracture of the proximal humerus. Clin Orthop Relat Res. 1996; (327):225–237. doi:10.1097/00003086-199606000-00028 [CrossRef]
- Moeckel BH, Dines DM, Warren RF, Altchek DW. Modular hemiarthroplasty for fractures of the proximal part of the humerus. J Bone Joint Surg Am. 1992; 74(6):884–889.
- Solberg BD, Moon CN, Franco DP, Paiement GD. Surgical treatment of three and four-part proximal humeral fractures. J Bone Joint Surg Am. 2009; 91(7):1689–1697. doi:10.2106/JBJS.H.00133 [CrossRef]
- Sperling JW, Cofield RH, Rowland CM. Neer hemiarthroplasty and Neer total shoulder arthroplasty in patients fifty years old or less. Long-term results. J Bone Joint Surg Am. 1998; 80(4):464–473.
- Chesser TJ, Langdon IJ, Ogilvie C, Sarangi PP, Clarke AM. Fractures involving splitting of the humeral head. J Bone Joint Surg Br. 2001; 83(3):423–426. doi:10.1302/0301-620X.83B3.11218 [CrossRef]
- Neviaser JS. Complicated fractures and dislocations about the shoulder joint. J Bone Joint Surg Am. 1962; 44(5):984–998.