DISEASE SUMMARY PAGE

Fractures in Bears

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Summary Information
Diseases / List of Physical / Traumatic Diseases / Disease summary
Alternative Names Broken bones in bears
Disease Agents
  • Fractures of the antebrachium in polar bears occurred when bears fell into moats (or were pushed by another bear), slipped on ice or were injured while playing. (J428.34.w1)
  • When the 25-hydroxyvitamin D levels of Ursus maritimus - Polar bears with fractures were assayed and compared to the normal range (135-690 nmol/L for captive and 135-870 nmol/L for free-ranging polar bears) six had concentrations below normal and one had a low-normal level (143 nmol/L); levels in the other four bears were normal. Those in the low to low-normal range came from two zoos. Two bears were confirmed to have sub-normal levels at the time of injury. It is possible that low Vitamin D levels may increase the susceptibility of polar bears to fractures. (J428.34.w1)
Infectious Agent(s) --
Non-infectious Agent(s)
Physical Agent(s)
General Description Fractures may occur in various bones; most are described in long bones, but fatal neck fractures also occur.
  • Fractures of the radius and/or ulna may occur in bears caught using an Aldrich leg snare. (J59.8.w1)
  • Fractures are seen occasionally in Ursus maritimus - Polar bears. (D247.7.w7)
  • Femoral fracture occurred in a yearling black bear darted while in a tree. (P9.2004.w4)
  • A survey of Ursus maritimus - Polar bear in the USA revealed four cases of concurrent fractures of the radius and ulna, three fractures of the radius only, two concurrent tibial and femoral fractures, one concurrent tibial and fibular fracture, one femoral fracture and one scapular fracture. Seven of the fractures occurred in bears under three years of age. Several fractures were irreparable. (J428.34.w1)
  • A wild Ursus americanus - American black bear cub found weak by a road was found to have an open fracture of the right femur, an open fracture of the left tibia and fibula, and pelvic asymmetry. (P62.9.w1)
  • A wild Ursus americanus - American black bear cub was found to have a fracture of the ischium, with bone penetrating the rectum and extending into the caudal aspect of the acetabulum; there was an associated subacute arthritis. (J1.35.w5)
  • A wild-born Ursus americanus - American black bear cub being hand-reared and rehabilitated fell and broke her neck in a freak accident. (D252.w27)
  • A wild-born Ursus americanus - American black bear cub presenting for hand-rearing had a healed fracture, but did not use the leg properly; bone infection was present. (D252.w27)
  • A wild-born Ursus americanus - American black bear cub presenting for hand-rearing had an odd gait; radiography showed healed fractures of the hips. Apart from a shuffling gait the bear behaved normally. (D252.w27)
  • A wild-born Ursus americanus - American black bear cub presented with a "shattered" front leg and a dislocated hip after being hit by a car. (D252.w27)
  • A 14-month-old male Ursus maritimus - Polar bear in a zoo fractured his lateral humeral condyl, and subluxated the medial condyle, in a fall. The bear showed acute non-weight-bearing lameness of the right forelimb. (P507.2005.w6)
  • In one Tremarctos ornatus - Spectacled bear, femoral fracture occurred due to trauma. (P77.1.w19)
Further Information Treatment
  • Fractures are usually repaired using internal fixation, particularly compression-plating techniques. (B64.26.w5)
    • Internal fixation is preferred, particularly for complicated fractures and in larger bears. (B16.9.w9)
    • For antebrachial fractures involving complete fractures of both radius and ulna, internal fixation is recommended to restore continuity of the weight-bearing column of bone in the limb. It may be possible to use external coaption to support internal fixation, but this may not be tolerated by the bear; if a cast is not tolerated, confinement to a small pen may assist healing. (J428.34.w1)
    • The temperament of the individual bear will affect healing. (J428.34.w1)
  • A cast may be used for a complete or incomplete fracture of one antebrachial bone only (the other bone acting as a splint during healing). Ideally the cast should reach from above the elbow distally to and including the paw, although the short brachium makes casting proximal to the elbow problematic. Interdigital cotton padding should be included to prevent development of sores. (J428.34.w1)
    • External fixation is a problem because the bear takes an interest in external devices and actively chew or claws at them, which can cause more severe damage than the original injury. (B64.26.w5)
    • If a cub chews on a cast, an Elizabethan collar can be fitted. (B16.9.w9)
  • Challenges to bear fracture treatment include:
    • External coaption devices may be destroyed by the bear. (J428.34.w1)
    • The bear may be stressed by confinement and isolation. (J428.34.w1)
    • Administering medication such as post-operative antibiotics. (J428.34.w1)
    • Repeated general anaesthesia is required for cast monitoring, cast changes and radiographic monitoring of healing. (J428.34.w1)
    • Social reintegration when the bear is returned to its enclosure. (J428.34.w1)
  • Wild bears sustaining a lower leg fracture during trapping [for experimental purposes] are generally released without treatment; available data indicates that Ursus americanus - American black bear with a fractured radius and/or ulna can survive well (in good physical condition at later capture) (J59.8.w1)

Case histories

  • An 18-year-old female Ursus maritimus - Polar bear with a closed, non-displaced, moderately comminuted transverse fracture of the mid-diaphyseal radius was treated by application of full-limb Plaster of Paris cast with integrated wire mesh (in 1974). The bear destroyed the cast within 48 hours and was then treated by being confined to a small pen for three months. At that time the fracture showed sufficient radiographic evidence of healing that the bear was returned to her enclosure. She recovered completely and lived for 23 years with no evidence of lameness.(J428.34.w1)
  • An eight-month-old female Ursus maritimus - Polar bear with a closed, mildly displaced, mildly comminuted short-oblique mid-diaphyseal fracture of the radius, with a large butterfly fracture cranially, and a similar fracture in the distal ulnar diaphysis, was treated using a nine-hole 4.5 mm broad dynamic compression plate (DCP) on the craniolateral surface of the radius, with a 3.5 mm cortical screw plus two 18-gauge circlage wires to stabilise the butterfly fragment, while a seven-hole 4.5 mm narrow DCP was placed on the ulna. The bear was then kept in a squeeze cage for 5-8 days, followed by a small pen. The bear rubbed at the incisions and paced. By one month the ulnar plate was broken, the radial plate was displaced and there was good callus formation. The cub was kept in the squeeze cage for a month then in the small pen for 1.5 months until there was radiographic evidence of healing, after which she was reintroduced to her mother and sibling. She became lame about three months later, possibly due to subluxation of the elbow associated with relative radius overgrowth secondary to synostosis of the proximal ulna and radius. (J428.34.w1)
  • A one-year-old male Ursus maritimus - Polar bear with a closed, complete, moderately displaced mildly comminuted short-oblique proximal radial diaphysis fracture with a butterfly fragment cranially and a similar but severely displaced closed mid-diaphyseal fracture of the ulna, was treated using a 12-hole 4.5 broad DCP on the craniolateral surface of the radius, with three 18-gauge circlage wires to stabilise the butterfly fragment, while a seven-hole 4.5 mm narrow DCP was placed on the caudolateral surface of the ulna. The cub was kept in a squeeze cage for 5-8 days then in a small pen. At three months, radiographs showed synostosis of the radius and ulna. At four months, due to concern about impairment of normal growth of the antebrachium, the implants were removed; correction of the synostosis was intended but was not possible (excessive risk of refracturing the bones). At five months radiography indicated adequate healing and the cub returned to exhibit. The bear recovered a good range of motion and died at 13.5 years old from cardiac disease. (J428.34.w1)
  • An eleven-year-old male Ursus maritimus - Polar bear with a closed complete moderately displaced mildly comminuted short-oblique mid-diaphyseal radius fracture and a complete, mildly displaced, closed, mildly comminuted fracture of the distal ulnar metaphysis with a small medial butterfly fragment was treated  with a six-hole 4.5 mm narrow DCP craniomedially on the radius, an 8-hole 4.5 mm narrow DCP craniolaterally on the radius and a 10-hole T-plate caudolaterally on the ulna. The bear was kept in a small pen until radiography showed adequate healing, then returned to exhibit. Axial rotation of the limb was decreased. Ten months postoperatively, lameness was noted, initially mild and intermittent, developing to chronic with occasional swelling as well as a decreased range of carpal motion and a subtle fixed pronation of the limb. Radiography at one year post fracture showed possible degenerative changes suggesting antebrachiocarpal joint osteoarthritis. Pain and lameness were treated with oral administration of a chondroprotectant and a NSAID.  (J428.34.w1)
  • Antibiotic were given for 1-3 days post-operatively in bears undergoing internal fixation of fractures. (J428.34.w1)
  • In a Ursus americanus - American black bear cub, the femur (open fracture) was trimmed back to viable tissue (about 3 inches removed) and the two segments were attached with cerclage wire. In a separate operation three days later, the left tibia and fibula, which were healing at right angles, had the callus broken down, were brought into near natural alignment and fixed using circlage wire and a figure-of-eight tension band. The cub healed well and was released a year later. (P62.9.w1)
  • A wild-born Ursus americanus - American black bear cub presenting for hand-rearing and found to have healed hip fractures was not treated, was released, and survived well until shot by a hunter. (D252.w27)
  • A 14-month-old male Ursus maritimus - Polar bear with a fractured his lateral humeral condyl, and subluxated medial condyle was treated surgically; surgery lasted four hours. The skin was incised (20 cm incision) over the lateral distal humerus and elbow joint, and blunt and sharp dissection used to expose the lateral condyle, epicondyle and joint. Following debridement and saline lavage, the fracture was manually reduced ("with some difficulty"), stabilised using two 18-gauge cerclage wires and interfragmentary compression was achieved with two 5.5 mm lag screws, one inserted into the exterior fossa through the humeral condyles, the other proximally, to provide rotational stability. Since the distal cerclage wire became loose once the interfragmentary compression was achieved, this was removed. The anconeus muscle was sutured (cruciate pattern, PDS USP 1), subcutaneous tissues were sutured with Polyglactin 910 USP 1 in a continuous pattern and the skin sutured with the same suture material in an interrupted cruciate pattern. A semiocclusive dressing was placed to protect the incision and a full limb cast applied with the carpus in flexion. Ketoprofen was given once (2 mg/kg intramuscularly) and cefazolin sodium was given at 10 mg/kg intravenously every two hours during surgery. The subluxation of the medial condyle was corrected by the fracture reduction and interfragmentary compression. Post-surgery, ketoprofen was given 1 mg/kg daily for three days orally in food, and cephalexin monohydrate was given at 15 mg/kg twice daily for 19 days. The bear twice removed his cast in the first week and it was then left off, with the bear in an indoor enclosure; he was fully weight bearing on the limb and radiography at three weeks showed callus formation across the fracture line. He was moved to a small outside enclosure, then a week later to a large enclosure with pool access (the surgical incision had healed well). Two months later, radiography showed a large callus and proper healing and the right humerus was stable on palpation. He was returned to his usual habitat with other bears and has remained active, with normal growth. (P507.2005.w6)
  • A femoral fracture in a Tremarctos ornatus - Spectacled bear was repaired by internal fixation [no further details available]. (P77.1.w19)
Associated Techniques
Host taxa groups /species

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