Cause of Device-Related Incident
Device factors

Clinical Specialty or Hospital Department
Clinical/Biomedical Engineering; OR / Surgery; Orthopedics

Device Factors
Design / labeling error

Document Type
Hazard Reports

External Factors
*Not stated

Mechanism of Injury or Death
Particulates

Support System Failures
*Not stated

Tampering and/or Sabotage
*Not stated

User Errors
*Not stated

UMDNS
Burs, Orthopedic [17-995]; Cutters, Meniscus [17-117]; Knives, Meniscus [12-248]

Blade Fracture of High-Speed Meniscus Cutters during Arthroscopic Surgery



Hazard [Health Devices Sep 1991;20(9):361-2]

Problem

In 1990, we received three reports from three different member hospitals regarding incidents in which the blade of a high-speed, power-driven arthroscopic meniscus cutter broke during knee surgery, depositing metal shavings in the operative site. In each case, the broken meniscus cutter was manufactured by a different company. The blade pieces were successfully removed from the patient in only one of these three incidents. Further review of ECRI's and U.S. Food and Drug Administration (FDA) databases yielded several dozen complaints about the presence of metallic fragments in the operative field following the use of these cutters during arthroscopic surgery.

The presence of even small metallic fragments within the body can result in an infection of either surgical or hematogenous origin. Bacteria that become engrafted on a foreign metallic surface in the body usually respond poorly to antibiotic medication, and arthrotomy is often required to remove the metallic bodies and any infected tissue. Moreover, because these meniscus cutters, which are powered by high-speed drive systems, can rotate at speeds in excess of 3,000 rpm, broken pieces of metal from the cutter's blade can become impacted in the surrounding tissues and cause serious injury.

Discussion

High-speed, power-driven meniscus cutters, available in both single-use and reusable models, were developed to reduce the amount of time necessary to resect tissue and cartilage during arthroscopic surgery. They have an inner shell surrounded by an outer sheath. The inner shell is a long, hollow, cylindrical shaft to which a cutting head is joined. The cutter's outer sheath contains an opening at its distal end through which the inner shell's cutting head operates (see figure). Cutting efficiency is directly related to the gap separating the inner shell's cutting head from the inside edge of the outer sheath. Reducing the distance separating these two cutting surfaces increases cutting performance; however, if this gap is reduced to the degree that the blade's rotating cutting surface is unable to spin freely, an amount of heat sufficient to cause blade failure may be produced.

Three main factors can cause the blades of meniscus cutters to break: 1) If either the inner shell or the outer sheath of the cutter becomes bent by the large cantilever forces encountered during surgery, the blade's two cutting surfaces may rub against each other, resulting in wear or breakage. 2) The cutter's inner shell is constructed of two pieces, which may become misaligned during manufacturing; this can cause either piece to scrape against the cutter's outer sheath, which can result in blade fracture. In addition, stresses produced during arthroscopic surgery may become concentrated at the seam where the two pieces join, further increasing the probability of blade breakage. 3) Either piece of the cutter's inner shell may be coated with a metallic compound to increase surface hardness, and excessive abrasion between the blade's two cutting surfaces may cause fragments of this metallic coating to shed into the operative field.

Action Taken

Several manufacturers of high-speed, power-driven meniscus cutters are modifying the blade design to reduce the likelihood of blade wear and breakage. Some modifications include manufacturing the blade's cutting head with very strong, wear-resistant stainless steel; increasing the thickness of the inner shell; or hardening the shaft.

Recommendations

  1. Be sure that the orthopedic surgeons in your institution who use high-speed, power-driven meniscus cutters are aware of the potential for blade wear and breakage.
  2. Do not reuse single-use blades.
  3. Examine the operative field for the presence of metallic materials before closure.
  4. Inspect the blade for damage or wear, which may indicate that metallic fragments or particles are present in the operative site. If you suspect or detect any such fragments or residue, thoroughly irrigate the joint and apply suction as required. In some instances, an x-ray of the joint may be necessary to pinpoint the exact location of the fragments.

UMDNS Terms

  • Burs, Orthopedic [17-995]
  • Cutters, Meniscus [17-117]
  • Knives, Meniscus [12-248]

Cause of Device-Related Incident

Device factor: Design/labeling error

Mechanism of Injury or Death

Particulates


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