679610HANDLaw et alArticleTrends in Open and EndoscopicCubital Tunnel Release in theMedicare Patient PopulationHAND 1 –5 American Association forHand Surgery 2016DOI: 10.1177/1558944716679610hand.sagepub.comTsun Yee Law1, Zachary S. Hubbard1, Lee Onn Chieng1,and Harvey W. Chim1AbstractBackground: Cubital tunnel syndrome (CUT) is the second most common peripheral neuropathy with an annual incidenceof 24.7 per 100 000, affecting nearly twice as many men as women. With increasing focus on cost-effectiveness and costcontainment in medicine, a critical understanding of utilization of health care resources for open and endoscopic approachesfor cubital tunnel release is of value. The purpose of this study was to evaluate the costs and utilization trends of openand endoscopic cubital tunnel release. Methods: We performed a retrospective review of a Medicare database within thePearlDiver Supercomputer (Warsaw, Indiana) for procedures performed from 2005 to 2012. Annual utilization, charges,reimbursement, demographic data, and compound annual growth rate were evaluated. Results: Our query returned 262 104patients with CUT, of which 69 378 (26.5%) and 4636 (1.8%) were surgically managed with open and endoscopic releaserespectively. Average charges were higher in endoscopic release ( 3798) than open release ( 3197) while reimbursementswere higher in open releases ( 1041) than endoscopic releases ( 866). Both were performed most commonly in the 65years age range. Conclusions: Despite the unexpectedly lower reimbursement rate with endoscopic release, endoscopyutilization is growing faster than open releases in the Medicare population. Lower reimbursement is likely related to lack ofa dedicated current procedural terminology (CPT) code for endoscopic cubital tunnel release.Keywords: cubital tunnel release, endoscopic, open decompression, ulnar nerve, minimal invasiveIntroductionCubital tunnel syndrome (CUT) is the second most common peripheral neuropathy with an annual incidence of24.7 per 100 000, affecting nearly twice as many men aswomen.9 There are many direct causes of CUT, yet a significant number of patients experience idiopathic neuropathy due to external compression and traction of the ulnarnerve.12 Nonsurgical management is recommended for themajority of patients; however, up to 42% fail conservativetreatment and are considered for surgery.3 Surgical management for ulnar nerve entrapment was first described in1816, and since that time, various treatment modalities havebeen described including decompression, transposition, andepicondylectomy.2,3,11Decompression is the most prevalent means of treatment, and can be performed endoscopically or with an openapproach.15 Recent studies have shown no difference in outcome between in situ decompression and more invasiveapproaches such as transposition.8 In addition, they haveconcluded that simple decompression is as efficacious asdecompression with transposition.8 As such, in recent years,in situ decompression has become the procedure of choicein many centers.Tsai and colleagues were among the first to introduce anendoscopic technique in 1999.17 Since then, a number of systems have been introduced and are in common usage. Theseinclude systems that rely on a cannulated push cut techniqueunder direct endoscopic visualization—Endorelease (Integra,Plainsboro, NJ), Clear cannula (AM Surgical, Smithtown,NY), and Segway.4 The Hoffman system (Storz) relies ondirect dissection under endoscopic visualization through asmall incision.7Recent studies have demonstrated favorable clinical outcomes with an endoscopic approach, including decreased1University of Miami Miller School of Medicine, FL, USACorresponding Author:Harvey W. Chim, Division of Plastic Surgery, University of Miami MillerSchool of Medicine, Clinical Research Building, 1120 N.W. 14th St.,4th Floor, Miami, FL 33136, USA.Email: [email protected]

2pain, scar tenderness, and numbness, and an expedited postoperative return to full recovery.11,14,18 Concerns for anendoscopic approach are that it can be technically demanding, with a possibility of injury to ulnar nerve, cutaneoussensory nerves, and subcutaneous veins if not properlyexecuted. Nevertheless, the popularity of endoscopicapproaches is increasing, likely due to patient desire for asmaller scar and faster recovery. A comparative study ofopen and endoscopic in situ decompression found that bothhad equivalent results, with less pain and higher satisfactionwith the endoscopic group.18 Conversely, the open grouphad a higher complication rate in this study.With increasing focus on cost-effectiveness and costcontainment in medicine, a critical understanding of utilization of health care resources for open and endoscopicapproaches for cubital tunnel release is of value. Identifyingthe specific demographic or socioeconomic contexts inwhich an endoscopic or open approach to CUT is used willallow surgeons to better manage patient expectation andallocation of health care resources.The purpose of this retrospective study of a national longitudinal database was to evaluate the costs and utilizationtrends of open and endoscopic approaches for decompression of the ulnar nerve within a large patient database.MethodsA retrospective review of a Medicare database within thePearlDiver Supercomputer (Warsaw, Indiana) was performed for patients undergoing open (OCUTR) or endoscopic cubital tunnel release (ECUTR) from 2005 to 2012.The PearlDiver database is a publicly available, HealthInsurance Portability and Accountability Act (HIPAA)compliant national database compiled from a collection ofprivate payer records. This database contains current procedural terminology (CPT) and International Classification ofDiseases, Ninth Revision (ICD-9) codes. This study wasexempt from institutional board review.Patients with CUT were identified by ICD-9 codes 354.2and 955.2. OCUTR was identified by CPT code 64718alone. Patients who had CPT 64718 linked with CPT 24305,24999, 24356, 29999, or 64999 were excluded from theOCUTR cohort. Per recommendations from the AmericanAssociation of Hand Surgery (AAHS), 64718 is coded with24305 for submuscular transposition, 24999 for subfascialor subcutaneous transposition, and 24356 for medial epicondylectomy. Excluding CPT 64718 linked with 29999 and64999, as seen below, would rule out patients who mighthave had an endoscopic procedure instead of an open one.Patients who underwent ECUTR were identified by linking CPT 29999 and 64999 with CUT ICD-9 codes. CPT29999 is a code billing for an unlisted arthroscopic procedure while CPT 64999 bills for an unlisted nerve procedure.Both can be used for billing for ECUTR as no dedicatedHAND CPT code exists for ECUTR. To ensure as much data accuracy as possible, we excluded patients from the ECUTRcohort with CPT 29999 and 64999 linked to 29830 (diagnostic elbow arthroscopy) and 29834-38 (elbow arthroscopy codes). This served to exclude patients who may havehad an unlisted elbow arthroscopy procedure coded withCPT 29999 or 24999. Coding CPT 64718 is specificallydefined by the Centers for Medicare and Medicaid services(CMS) as an open procedure hence claims submitted forECUTR using CPT 64718 would likely have been deniedand excluded from the database. Annual utilization, charges,reimbursement, demographic data, and compound annualgrowth rate (CAGR) were also evaluated.Statistical analysis of this study was performed withMinitab version 17 (State College, Pennsylvania) and wasprimarily descriptive with paired t tests to determine significance where appropriate.ResultsOur query returned 262 104 CUT patients, of which 67 883(25.9%) and 4636 (1.8%) were surgically managed withOCUTR and ECUTR, respectively (remainder treated conservatively or spontaneously resolved). CAGR was significantly higher in ECUTR (12.6%) than OCUTR (8.6%) (P .001). Annual growth and utilization of both techniques isdetailed in Table 1 and Figure 1. Average charges werehigher in ECUTR ( 3798) than OCUTR ( 3197) whilereimbursements were higher in OCUTR ( 1041) thanECUTR ( 866) (Table 2, Figure 2). The shortfall in reimbursement was noted to be growing with each year, butmore in ECUTR. In 2012, the shortfall in reimbursementfor ECUTR was 1.5 times that for OCUTR.Both OCUTR and ECUTR were performed most commonly in the under 65 years age range (OCUTR 35.6%,ECUTR 34.7%) followed by the 65 to 69 years age range(OCUTR 22.7%, ECUTR 21.9%) (Table 3). OCUTR wasperformed slightly more in males (51.6%) than females(47%) and ECUTR was essentially equal (female, 49.1%;male, 48.8%) (Table 4). Both approaches were utilized mostin the southern US geographic region (OCUTR 40.6%,ECUTR 41.9%) (Table 5).DiscussionSurgical approaches for treating CUT have traditionallybeen through an open approach but the endoscopic approachis increasingly used. This is likely due to an increase in thenumber of systems available and also greater patient andsurgeon awareness of endoscopic techniques. The purportedadvantage of an endoscopic approach is a smaller incisionwith decreased soft tissue dissection and potentially morerapid recovery with less scarring, translated into fasterreturn to work (RTW) times for patients.17 Endoscopic

3Law et alTable 1. Annual Open and Endoscopic AGRCUTOCUTR26 31528 46828 60630 10432 11835 21539 22542 053262 1046.9%64517314723377648556986310 86511 33269 3788.4%Growth13.4% 872846463612.6%Growth7.1%1.0%13.1%14.2%54.5%9.8% 3.0%Note. CUT cubital tunnel syndrome; OCUTR open cubital tunnel release; ECUTR endoscopic cubital tunnel release; CAGR compound annualgrowth rate.Figure 1. Annual open and endoscopic cubital tunnel releasegrowth.Note. OCUTR open cubital tunnel release; ECUTR endoscopiccubital tunnel release.approaches cost more initially to set up, but economic benefits advocated include costs savings from decreased surgical and anesthesia times and faster RTW times forpatients.14,16 Currently, there is a paucity of literature investigating the trends in utilization and reimbursement of theseapproaches. The primary finding of this study was thatECUTR utilization is growing faster than OCUTR but thereimbursement shortfall for ECUTR is increasing.The results of this study indicate that ECUTR (CAGR12.6%) is becoming an increasingly popular approach compared with OCUTR (CAGR 8.4%). A study by Bain andWatts found that the proportion of patients satisfied with theoutcome of OCUTR was 9 of 15 (60%) and 15 of 19 (79%)for ECUTR.18 Furthermore, two studies have shown thatboth approaches have similar long-term functional outcomes, but with the OCUTR approach, both studies found a20% and 23.7% rate of postoperative numbness comparedwith none in ECUTR, respectively.6,18Our study found that the average Medicare charges werehigher in ECUTR but reimbursements were unexpectedlylower compared with OCUTR during our 8-year studyinterval (2005-2012). The charges and Medicare reimbursements of OCUTR and ECUTR have not been adequatelystudied. One study investigated transposition with decompression and determined that the mean cost of decompression was 6447 (95% confidence interval [CI], 5079- 7814), whereas transposition was 6738 (95% CI, 5371- 8105) (P .807).15 However, this study did not differentiate between open or endoscopic procedures andplaced Medicare, Medicaid, worker’s compensation, andprivate insurance as one value. To date, there is no dedicated CPT code for ECUTR, thus the necessity to utilize anunlisted CPT 29999 or 64999 code may account for thelower comparative reimbursement.Both approaches for CUT in our study were mostly usedin patients younger than 65 years of age. These results aresupported by a recent retrospective study on the demographics of CUT that found an average age of 55 12.5years.10 The results of our study showed that OCUTR wasperformed at a slightly higher rate in males (52.4%) compared with females (47.6%) and was relatively equal forECUTR (male, 49.9%; female, 50.1%). A multicenter studyof different techniques for cubital tunnel release with meanfollow-up of 92 months showed a similar demographic,with 56.8% of procedures performed on males.1 Like thatstudy, we found that CUT is not gender preferential (male,50.6%; female, 49.4%) which is contrary to previous studies that suggest male dominance in CUT.5,13This study is not without limitations. The PearlDiverdatabase is reliant upon accurate CPT or ICD coding whichcreates the potential for a reporting bias. In addition, thereis no dedicated CPT or ICD code for ECUTR which mayalso create a reporting bias. However, the strength of thisstudy is the large patient population that was analyzed. Inaddition, our study investigates the utilization and reimbursement trends of OCUTR and ECUTR that has not beenadequately studied previously.

4HAND Table 2. Average Charges and 2AverageOCUTR chargesOCUTR reimbursementShortfallECUTR chargesECUTR reimbursementShortfall 2450 2621 2810 3006 3252 3503 3747 4002 3174 878 929 971 999 1070 1102 1149 1142 1030 1572 1692 1839 2007 2182 2401 2598 2860 2144 2427 2803 2908 2844 4055 5179 4649 5516 3798 621 656 690 633 872 1209 1075 1169 866 1806 2147 2218 2211 3183 3970 3574 4347 2932Note. OCUTR open cubital tunnel release; ECUTR endoscopic cubital tunnel release.Table 4. Open and Endoscopic Release by Gender.GenderFemaleMaleUnknownCUTOCUTRECUTR113 938 (48.6%)116 837 (49.8%)3794 (1.6%)31 458 (47.0%)34 575 (51.7%)902 (1.3%)1381 (49.1%)1373 (48.8%)61 (2.2%)Note. CUT cubital tunnel syndrome; OCUTR open cubital tunnelrelease; ECUTR endoscopic cubital tunnel release.Table 5. Open and Endoscopic Release by Region.RegionFigure 2. Annual average charges, reimbursements, andshortfalls for open and endoscopic cubital tunnel release.Note. OCUTR open cubital tunnel relea