The Cold, Hard Facts of Cryotherapy in Orthopedics

ADVANCED CRYOTHERAPY DEVICES

Several recent studies explored the relative postoperative benefits of advanced cryotherapeutics in lieu of the traditional ice pack.^6,7,17-21 As reflected in Table 2, these studies, much like the literature comparing cryotherapy to the control, do not reveal significant benefits of continuous flow cryotherapy after surgery. In fact, the only outcome measure that was found to differ significantly in more than 1 study was ROM. Though the makers of advanced cryotherapy systems market them as a vast improvement over traditional forms of cold therapy, there is insufficient evidence to support such claims. Even the most robust study that included 280 patients failed to show significant differences in the analgesic use and ROM after surgery.²⁰ Of note, all but 1 study compared traditional and advanced cryotherapy following procedures on the knee. Additional research exploring outcomes after surgery on other joints is necessary before any conclusions can be made regarding postoperative benefits or risks within orthopedics more generally.

RISKS AND ADVERSE EFFECTS OF CRYOTHERAPY

A rigorous analysis of the benefits of cryotherapy ought to incorporate other factors in addition to improvements in analgesic consumption, VAS score, and ROM. These include the financial and time investment involved in the use of continuous flow cryotherapy, which the majority of studies do not consider. Though many authors acknowledge that continuous flow cryotherapy is expensive, to our knowledge, none have yet performed a formal economic analysis of the cost of advanced cryotherapy to the patient as well as to the healthcare system at large.^{6,7,13,18,22-24} Dickinson and colleagues²⁴ calculated the total cost of cryotherapy and rehabilitation following rotator cuff repair, but addressed only the up-front cost of the cold therapy system. For context, Table 3 summarizes the retail cost of the most popular cryotherapy devices on the market. Based on this information alone, it seems reasonable to conclude that these systems are associated with significantly more cost than traditional forms of cold therapy, and therefore would be an undesirable option for patients or hospital systems. Nevertheless, cost considerations are more nuanced than a simple comparison of price, necessitating more advanced economic analyses. Substantial savings may be on the table if future studies are able to prove postoperative cryotherapy shortens hospital stays, reduces medication costs, and results in fewer physical therapy sessions. Moreover, if all this is true, patients may experience quicker recovery and have overall greater post-procedure satisfaction.

Table 3. Cost of Most Popular Cryotherapy Units

Patient education required for optimal use of advanced cold therapy is another aspect of cryotherapy that is poorly represented in the literature. As Dickinson and colleagues²⁴ point out, because it eliminates some dependency on the patient to remember to ice appropriately, continuous flow cryotherapy may have a positive impact on compliance and therefore yield improved outcomes.²⁴ Hospital staff may be required to spend additional time with patients. However, this is necessary to ensure proper understanding on how to operate the system and avoid adverse outcomes. Patients may also find the large coolers inconvenient and may therefore be reluctant to use them, finding traditional ice more manageable. Future studies should consider gathering data on patient education, compliance, and overall reception/satisfaction to complete a more holistic investigation of the role of postoperative cryotherapy in orthopedics.

Cryotherapy is not without adverse outcomes, which have been documented primarily in the form of case study reports. Relevant case studies cited adverse outcomes including frostbite/skin loss, compartment syndrome, and perniosis as potential dangers of postoperative cryotherapy in orthopedics (Table 4).^25-30 As an example, a patient recovering from patellar-tendon repair experienced bilateral frostbite and skin loss following 2 weeks of uninterrupted use of cryotherapy without any barrier between his skin and the system.²⁹ A similar case study described 2 female patients, one recovering from a TKA and the other from a tibial revision of arthroplasty, who used cryotherapy systems without cessation and experienced frostbite and skin necrosis over the entirety of their knees.²⁶ A third case study exploring 4 incidents of patellar frostbite and necrosis following knee arthroscopies proposed that poor patient understanding of proper cryotherapy use as well as poor recognition of the signs of frostbite contributed to these adverse outcomes. Furthermore, the cryotherapy brace used by all 4 patients included a feature designed to counteract patellar inflammation that also may have increased the likelihood of frostbite in this area due to poor tissue insulation. The authors noted that following the incidents, the makers of the brace removed patellar coverage to prevent future occurrences.³⁰

Abbreviations: ACL, anterior cruciate ligament; TKA, total knee arthroplasty.

Frostbite linked to cryotherapy has also occurred following orthopedic procedures outside the knee. Brown and Hahn²⁵ described 2 young females who developed skin necrosis following podiatric surgeries and constant cold therapy for roughly a week. Notably, 1 patient had cold sensitivity, which likely put her at an increased baseline risk of experiencing frostbite while using cryotherapy. Tissue necrosis is not the only danger of cold therapy discussed in this study. Surprisingly, 1 patient also developed compartment syndrome.²⁵ Khajavi and colleagues²⁷ also documented postoperative compartment syndrome in a patient following an arthroscopic osteochondral autograft transfer, which they attributed to reperfusion injury in the wake of first-degree frostbite. Hospital personnel also instructed this patient to use his cryotherapy system without interruption at the coldest temperature tolerable, contrary to manufacturer’s instructions.²⁷

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