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Results of Single-Incision Distal Biceps Tendon Repair for Early-Career Upper-Extremity Surgeons

Open AccessPublished:October 17, 2022DOI:https://doi.org/10.1016/j.jseint.2022.09.013

      ABSTRACT

      Background

      The purpose of this investigation was to assess surgical outcomes after distal biceps tendon (DBT) repair for upper-extremity surgeons at the beginning of their careers, immediately following fellowship training. We aimed to determine if procedure times, complication rates and clinical outcomes differed during the learning curve period for these early-career surgeons.

      Methods

      All cases of DBT repairs performed by 2 fellowship trained surgeons from the start of their careers were included. Demographic data as well as operative times, complication rates, and patient reported outcomes were retrospectively collected. A cumulative sum chart (CUSUM) analysis was performed for the learning curve for both operative times and complication rate. This analysis continuously compares performance of an outcome to a predefined target level.

      Results

      A total of 78 DBT repairs performed by the two surgeons were included. In the CUSUM analysis of operative time for surgeon 1 and 2, both demonstrated a learning curve until case 4. In CUSUM analysis for complication rates, neither surgeon 1 or surgeon 2 performed significantly worse than the target value and learning curve ranged from 14-21 cases. Mean QuickDASH (10.65±5.81) and VAS pain scale scores (1.13±2.04) were comparable to previously reported literature.

      Conclusions

      These data suggest that a learning curve between 4-20 cases exists with respect to operative times and complication rates for DBT repairs for fellowship trained upper-extremity surgeons at the start of clinical practice. Early-career surgeons appear to have acceptable clinical results and complications relative to previously published series irrespective of their learning stage.

      Keywords

      Distal biceps tendon (DBT) ruptures are frequently encountered in upper-extremity clinics, with an incidence around 2.55 per 100,000 patient-years.
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      The purpose of this investigation was to assess surgical outcomes after surgical repair of acute DBT ruptures performed by upper-extremity surgeons at the beginning of their careers, immediately following fellowship training in hand or upper extremity. We aimed to determine if procedure times, complication rates and clinical outcomes differed during the learning curve period for these early-career upper-extremity surgeons. We hypothesized that DBT repair would have a small learning curve and that surgical outcomes would be similar to those reported in previously published series
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      MATERIALS AND METHODS

      Institutional review board approval was obtained for this retrospective investigation.
      We used our electronic billing database to identify all cases of DBT repair from August 2016 to December 2020. Patients were included if they were 18 years of age or older. Cases involving DBT reconstruction and cases with less than 6 months of follow-up time were later excluded from the clinical outcomes analysis. All cases were performed consecutively at the start of clinical practice by one of two fellowship trained upper-extremity surgeons. The surgeons started clinical practice immediately after completing fellowship training (Surgeon 1 in August 2016, Surgeon 2 in August 2017). Cases were performed within a rural, Level I trauma center which is part of an integrated, academic, tertiary referral center in the northeastern United States. All DBT repairs utilized the single-incision technique. The method of tendon fixation employed varied by surgeon during the study period, including repair with a cortical suture button or suture anchor.
      Baseline demographics and surgical outcomes were recorded via manual chart review. Analysis was performed on a per-case, as opposed to a per-patient basis to account for patients with bilateral DBT repairs. Demographics recorded included age, sex, laterality, tobacco use, marital status, employment status, medical comorbidities as well as the presence of any mental, behavioral or neurodevelopmental disorders (defined as any ICD-10 codes from F01-F99). The surgical variables recorded included operative times and fixation method. Operative times were defined as time from incision until the placement of the dressing. In cases where the tendon could not be retrieved from the incision on the volar forearm, we recorded whether a second supplemental incision over the musculotendinous junction was utilized for tendon retrieval.
      Postoperatively, patient reported outcome measures (PROMs) including QuickDASH and visual analog pain scale (VAS) were collected along with range of motion (ROM) measurements. All ROM measurements were obtained by a certified occupational hand therapist using a manual goniometer. Postoperative complications were also recorded. Cases with a sensory neuropraxia of either the radial sensory or lateral antebrachial cutaneous (LABC) nerve were defined as “resolved” if the sensory symptoms resolved during the study period or “unresolved” if the patient had persistent subjective sensory symptoms at the time of final follow-up. Superficial infection was defined as an early postoperative wound infection that required local wound care and/or oral antibiotics but did not require a return to the operating room for débridement. Deep infection was defined as any case that required a return to the operating room for débridement and irrigation. Any case of suspected re-rupture after repair was confirmed with either a postoperative ultrasound or MRI.

      Statistics:

      Descriptive statistics were utilized for patient demographics and clinical outcomes when comparing cases characteristics between the two surgeons. Mean and standard deviation was reported for continuous variables while total count and frequency was reported for categorical data. Categorical data was analyzed using Chi-squared (or Fisher’s Exact where appropriate) while continuous variables were analyzed using a 2-tailed Independent sample student’s t-test. The primary outcome variables were rates of complications and operative times for early career surgeons during the potential learning curve period. Complication rates were reported as frequencies. To investigate an association between number of completed cases and operative time, a linear regression analysis was performed for each surgeon. A two-sided type I error rate of 5% was used for all comparisons. No attempt was made to control for multiplicity of testing.

      CUSUM Analysis:

      A cumulative sum (CUSUM) analysis was performed to identify learning curve stages for operative times and complication rate. The CUSUM analysis continuously compares performance of an outcome to a predefined target level. This statistical analysis represents the most appropriate statistical method for evaluating a learning curve of a surgical procedure.
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      • Cook R.J.
      • Farewell V.T.
      • Treasure T.
      Monitoring surgical performance using risk-adjusted cumulative sum charts.
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      For operative times, our target rate was defined as the mean values for each surgeon respectively.
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      • Abboud J.A.
      • Lutsky K.F.
      • et al.
      A Prospective Evaluation of Early Postoperative Complications After Distal Biceps Tendon Repairs.
      All complications were included in this predefined target rate, including transient sensory neuropraxia. Further analysis on complication rates was conducted based on methodology outlined by Fu et al.
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      Each case was assigned a value of “0” if there were any complications postoperatively or “1” if there were no complications (TABLE 1). Complications included presence of neuropraxia at any time, superficial or deep infection, re-rupture, or reoperation for any reason.
      Table 1.CUSUM values were calculated as (1-s)+CUSUM for cases with complications and CUSUM-s for cases without. Cases with complications were coded at 0. Cases without complications were coded as 1
      CUSUM Variable FormulaValue
      Target complication rate44%
      P00.44
      P1 = 2xP00.88
      α0.05
      β0.2
      P = ln(P1/P0)0.693
      Q = ln[(1-P0)/(1-P1)]1.540
      S = Q/(P+Q)0.690
      1-S0.310
      a = ln[(1-β)/α]2.773
      b = ln[(1-α)/β]2.558
      H0 = b/(P+Q)-0.698
      H1 = a/(P+Q)1.241
      The resulting cumulative sum curve graphs (Figures 1a-b, 3a-b) from this analysis show on the horizontal axes all consecutive patients in a chronological order. The vertical axes show the cumulative performance on the metric, compared to the target level.
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      • Watters D.A.
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      CUSUM values were visually evaluated for both deviation from the target rate as well as a plateauing of data points, indicative of performance stabilization. A downward trend of the CUSUM graph indicates success and an upward trend indicates failure. A learning curve can be determined when the cumulative sum curve indicates an upward trend in the first phase, also called learning phase, while a downward trend can be determined in a secondary phase, also called consolidation phase. In a final third phase, also called the mastery phase, performance reaches an optimal steady level.
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      Figure thumbnail gr1
      Figure 1aCUSUM analysis of operative time for surgeon 1 across consecutive distal biceps repairs. b. CUSUM analysis of operative time for surgeon 2 across consecutive distal biceps.
      Statistical significance was calculated with α=0.05 and β=0.2 According to Fraser et al, “when the CUSUM score remains above the decision limit h1, the actual failure rate is significantly greater than the acceptable failure rate, with a probability of type I error equal to α. When the CUSUM score remains below the decision limit h0, the actual failure rate does not differ significantly from the acceptable failure rate, with a probability of type II error equal to β”.
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      RESULTS

      During the study period, a total of 78 DBT repairs were performed by the two surgeons and included for CUSUM analysis (Appendix 1). All repairs were performed within 8 weeks from the time of injury. There were 24 cases included in CUSUM analysis for surgeon 1 and 54 cases included for surgeon 2. There were 21 cases with less than 6 months of clinical follow-up or lacking appropriate PROM assessments and excluded from clinical PROM analysis, leaving 57 total cases for demographic and case characteristic analysis. For clinical analysis, surgeon 1 performed 18 cases (32%) whereas Surgeon 2 performed 39 cases (68%) during the study period. Surgeon 2 utilized cortical button fixation for all 39 of their cases (100%), whereas Surgeon 1 utilized a both anchor and cortical button fixation.
      Table 2 summarizes the baseline demographics for included cases. The majority of cases were male (98%) and mean age was 49 years (range; 33-78). Tables 3 and 4 include surgical details, outcomes, and complications. There was an overall complication rate of 53% (95% CI [40%-66%]). The most reported complication was sensory neuropraxia, which occurred in 27 cases. The average clinical follow-up was 20 months (range; 6-60). Mean operative time was 70 minutes (range; 27-165) with a 95% confidence interval of [62.04-77.54], but this differed between surgeons (103 v 54 minutes, p<.001). At the time of final follow-up, the mean QuickDASH and VAS pain scores were 10.65 (range; 0-61.36) and 1.13 (range; 0-8) respectively.
      Table 2Baseline demographics for the 57 cases of distal biceps tendon repair performed during the study period
      ALLSURGEON 1 CLDSURGEON 2 LCGP-Value
      Cases, (n)571839-
      Age in years, mean (SD)49.12 (±9.43)49.33 (±10.67)49.03 (±8.94).91
       Interquartile range12.7510.515.25
       Median49.54850.5
       Maximum787864
       Minimum333533
      Male, n(%)56 (98%)18 (100%)38 (97%)1.0
      Laterality right, n(%)31 (54%)10 (56%)21 (54%)1.0
      White race, n (%)57 (100%18 (100%)39 (100%)-
      BMI, mean (SD)32.51 (±6.64)32.60 (±5.35)32.47 (±7.22).95
       Interquartile range6.725.748.54
       Median31.2430.3132.23
       Maximum59.1843.759.18
       Minimum19.3725.4919.37
      Active Tobacco use, n(%)10 (17%)4 (22%)6 (15%).71
      Diabetes, n(%)6 (10%)1 (5%)5 (13%).65
      Rheumatoid Arthritis, n(%)0 (0%)0 (0%)0 (0%)-
      ASA Rating, n (%).94
       ASA 1-244 (77%)14 (78%)30 (78%)
       ASA 3-413 (23%)4 (22%)9 (23%)
      Mental, Behavioral or Neurodevelopmental Disorder, n(%)14 (25%)4 (22%)10 (26%)1.0
      Married, n(%)43 (73%)13 (72%)30 (77%).96
      Employed, n(%)44 (75%)14 (78%)30 (77%)1.0
      Insurance Type, n(%).041*
       Private Insurance46 (81%)13 (72%)33 (85%)
       Medicaid / Medical Assistance1 (2%)0 (0%)1 (3%)
       Medicare3 (5%)3 (17%)0 0%)
       Self-Pay1 (2%)1 (6%)0 (0%)
       Other6 (11%)1 (6%)5 (13%)
      Worker’s Compensation4 (7%)1 (6%)3 (8%)1.0
      *Indicates P-value <.05
      **Indicates P-value <.01
      Table 3Surgical details and outcomes for the 57 cases of distal biceps tendon repair performed during the study period
      ALLSURGEON 1SURGEON 2P-Value
      OPERATIVE DETAILS
      Cases, (n)571839-
      Operative time in minutes, mean (SD)69.79 (±29.87)103.06 (±26.56)54.44 (±15.25)<.001**
       Interquartile range38.753921.5
       Median63.59750.5
       Maximum16516589
       Minimum277227
      Use of supplemental incision for tendon retrieval, n (%)6 (11%)0 (0%)6 (15%).16
      Method of Fixation, n(%)<.001**
       Suture anchors13 (23%)13 (72%)0 (0%)
       Bicortical endobutton13 (23%)0 (0%)13 (33%)
       Unicortical endobutton31 (54%)5 (28%)26 (67%)
      SURGICAL OUTCOMES
      Months follow-up, mean (SD)20.02 (±13.40)26.39 (±18.65)17.08 (±9.00).057
       Interquartile range1428.7511.5
       Median142113.5
       Maximum606043
       Minimum666
      Range of Motion, mean degrees (SD)
      Flexion136.60 (±14.65)140.00 (20.00)135.21 (±11.85).27
       Interquartile range2016.2516.25
       Median135150134
       Maximum160160150
       Minimum7575110
      Flexion-extension arc135.05 (±16.59)139.69 (±20.12)133.15 (±14.78).19
       Interquartile range202015.5
       Median135150131.5
       Maximum160160150
       Minimum757595
      Pronation83.02 (±9.30)85.31 (±7.63)82.08 (±9.84).25
       Interquartile range106.2510
       Median859085
       Maximum909090
       Minimum456545
      Supination82.42 ±(9.03)83.75 (±9.57)81.87 (±8.87).49
       Interquartile range1011.2510
       Median859081
       Maximum909090
       Minimum606560
      Patient Reported Outcome Measures, mean (SD)
      VAS Pain Scale1.13 (±2.04)0.72 (±1.77)1.32 (±2.14).31
       Interquartile range102
       Median000
       Maximum878
       Minimum000
      QuickDASH10.65 (±15.81)10.42 (±17.28)10.76 (±15.33).94
       Interquartile range14.7813.6411.36
       Median4.552.274.55
       Maximum61.3660.1561.36
       Minimum000
      *Indicates p-value <.05 ;
      **Indicates p- value <.01
      Table 4Complications after distal biceps tendon repair for surgeon 1 and surgeon 2
      COMPLICATIONS
      ALL N=57SURGEON 1 N=18SURGEON 2 N=39P-Value
      Cases with any complications, n (%)30 (53%)9 (50%)21 (54%)1.0
      Sensory neuropraxia, n(%)27 (47%)7 (39%)20 (51%).56
       Resolved18 (32%)5 (28%)13 (33%).66
       Unresolved9 (16%)2 (11%)7 (18%)
      Time from surgery to Neuropraxia resolution, mean (SD)107.33 (±90.07)124.60 (±138.24)100.69 (±70.37).63
      Superficial Infection, n(%)1 (2%)0 (0%)1 (3%)1.0
      Deep infection, n(%)0 (0%)0 (0%)0 (0%)-
      Re-rupture, n(%)3 (5%)2 (11%)1 (3%).23
      Reoperation, n(%)2 (4%)2 (11%)0 (0%).096
      Posterior interosseous nerve injury, n (%)0 (0%)0 (0%)0 (0%)-

      Operative Time:

      In the CUSUM analysis of operative time for surgeon 1 and 2, both demonstrated a learning curve until case 4. Surgeon 1 had a consolidation of performance until case 17, where there is a secondary inflection point representing the start of a plateauing of performance from case 18-24 (Figure 1a, Table 5). Surgeon 2 had a consolidation of performance until the secondary inflection point at case 36, after which the upward trend back to target represents a plateauing of performance from case 37-54 (Figure 1b). Figure 2 displays a linear regression model on operative time and case volume for surgeon 1 and surgeon 2. Surgeon 1 had an adjusted R2 value of 0.021 and surgeon 2 had an adjusted R2 value of 0.293 (Figure 2).
      Table 5CUSUM based competency phases for surgeon 1 and surgeon 2
      Competency MeasureSurgeon 1Surgeon 2
      Learning Curve PhaseConsolidation PhaseMastery PhaseLearning Curve PhaseConsolidation PhaseMastery Phase
      Operation time1st - 4th cases5th - 17th cases18th - 24th cases1st – 4th case5th - 36th cases37th - 54th case
      Complication rate1st - 14th cases15th - 24th cases-1st -21st case22nd - 49th case50th – 54th
      Figure thumbnail gr2
      Figure 2Distal bicep operative repair time based on cases completed for 2 surgeons.

      Complication Rate:

      In CUSUM analysis of complication rate, neither surgeon 1 or surgeon 2 performed significantly worse than the target value. Surgeon 1 had a consolidation of performance occurring after approximately 14 cases and performed significantly better than the target value after 16 cases (Figure 3a, Table 5). In contrast, Surgeon 2 had a consolidation of performance occurring after case 21 (Figure 3b) and performed significantly better than target value consistently after case 22. This suggests a 14-case learning curve for Surgeon 1 and a learning curve of 21 cases for Surgeon 2.
      Figure thumbnail gr3
      Figure 3aCUSUM analysis of complication rate for surgeon 1 across consecutive distal biceps repairs where h1 is defined as a statistically significant “unacceptable” rate of performance and h0 is defined as a statistically significant “acceptable” rate of performance. b. CUSUM analysis of complication rate for surgeon 2 across consecutive distal biceps repairs where h1 is defined as a statistically significant “unacceptable” rate of performance and h0 is defined as a statistically significant “acceptable” rate of performance.
      Table 6 includes a comparison of results reported in our series as well as results from 6 prior recent published series. The complication rate reported in this study were within the range of previously reported rates (33%-73%).
      Table 6Comparison of our results to other series of single-incision distal biceps repairs published in past ∼5 years
      Our SeriesSeries 1 Huynh et al1Series 2 Ford et al2Series 3 Matzon et al3Series 4 Siebenlist et al4Series 5 Cain et al5Series 6 Dunphy et al6
      Cases with single approach, (n)576065211224188639
      Fixation methodsCortical button

      Suture anchor
      Cortical buttonCortical button (±Interference screw)

      Suture anchor

      Bone tunnel
      Cortical button

      Suture anchor
      Cortical buttonCortical button

      Suture anchor

      Bone tunnel
      Cortical button (±Interference screw)

      Suture anchor
      Age in years, mean (SD)49.12 (±9.43)46.1 (±7.6)4948.7494848
      Operative time in minutes, mean (SD)69.79 (±29.87)NRNRNRNRNR56.2
      Months follow-up, mean (SD)20.02 (±13.40)44.4 (±20.4)5.63.928 (±16)9.749
      Range of Motion, meanº (SD)
       Flexion136.60 (±14.65)134 (±11)NRNR126.7NR135
       Flexion-extension arc135.05 (±16.59)134NRNR126.5NR132.9
       Pronation83.02 (±9.30)87 (±9)NRNR85NRNR
       Supination82.42 ±(9.03)81 (±16)NRNR82.2NRNR
      Patient Reported Outcome Measures, mean (SD)
      VAS Pain Scale1.13 (±2.04)NRNRNR0.7NRNR
      QuickDASH10.65 (±15.81)7.9 (±11.4)NRNR3.8 (±7.6)NRNR
      Cases with any complications, n (%)30 (53%)44 (73%)216 (33%)50 (45%)NR70 (37%)243 (38%)
      Sensory neuropraxia, n(%)27 (47%)7 (12%)149 (23%)47 (42%)2 (8%)62 (33%)186 (29%)
      Resolved18 (32%)NRNRNR2 (8%)186 (100%)
      Unresolved9 (16%)NRNRNR0 (0%)0 (0%)
      Superficial Infection, n(%)1 (2%)NRNRNR0 (0%)3 (2%)NR
      Deep infection, n(%)0 (0%)NRNR0 (0%)0 (0%)NRNR
      Rerupture, n(%)3 (5%)3 (5%)13 (2%)2 (2%)1 (4%)4 (2%)10 (2%)
      Reoperation, n(%)2 (4%)NR28 (4.3%)2 (2%)3 (13%)6 (3%)15(2%)
      Posterior interosseous nerve injury, n (%)0 (0%)NR12 (1.8%)NR0 (0%)7 (4%)5 (1%)
      1. Huynh T, Leiter J, MacDonald PB, Dubberley J, Stranges G, Old J, Marsh J. Outcomes and complications after repair of complete distal biceps tendon rupture with the cortical button technique. JBJS Open Access. 2019 Jul;4(3).
      2. Ford SE, Andersen JS, Macknet DM, Connor PM, Loeffler BJ, Gaston RG. Major complications after distal biceps tendon repairs: retrospective cohort analysis of 970 cases. Journal of Shoulder and Elbow Surgery. 2018 Oct 1;27(10):1898-906.
      3. Matzon JL, Graham JG, Penna S, Ciccotti MG, Abboud JA, Lutsky KF, Beredjiklian PK. A prospective evaluation of early postoperative complications after distal biceps tendon repairs. The Journal of Hand Surgery. 2019 May 1;44(5):382-6.
      4. Siebenlist S, Schmitt A, Imhoff AB, Lenich A, Sandmann GH, Braun KF, Kirchhoff C, Biberthaler P, Buchholz A. Intramedullary cortical button repair for distal biceps tendon rupture: a single-center experience. The Journal of Hand Surgery. 2019 May 1;44(5):418-e1.
      5. Cain RA, Nydick JA, Stein MI, Williams BD, Polikandriotis JA, Hess AV. Complications following distal biceps repair. The Journal of hand surgery. 2012 Oct 1;37(10):2112-7.
      6. Dunphy TR, Hudson J, Batech M, Acevedo DC, Mirzayan R. Surgical treatment of distal biceps tendon ruptures: an analysis of complications in 784 surgical repairs. The American Journal of Sports Medicine. 2017 Nov;45(13):3020-9.

      DISCUSSION

      In assessing surgical outcomes after DBT repair for upper-extremity surgeons at the beginning of their careers, we reported a mean postoperative VAS Pain scale and QuickDASH of 1.13 and 10.65 respectively. Results from our series (which included two surgeons within their learning-curve period) are similar to those reported by prior authors of recent series involving single incision DBT repairs. Both Huynh et al and Siebenlist et al reported postoperative QuickDASH scores of 7.9 and 3.8 respectively following DBT repair.
      • Huynh T.
      • Leiter J.
      • MacDonald P.B.
      • Dubberley J.
      • Stranges G.
      • Old J.
      • et al.
      Outcomes and complications after repair of complete distal biceps tendon rupture with the cortical button technique.
      ,
      • Siebenlist S.
      • Schmitt A.
      • Imhoff A.B.
      • Lenich A.
      • Sandmann G.H.
      • Braun K.F.
      • et al.
      Intramedullary cortical button repair for distal biceps tendon rupture: a single-center experience.
      Our results obtained by surgeons immediately following upper-extremity fellowship training are similar to those from large published series by experienced surgeons, suggesting that surgeon experience may not be associated with substantial changes in patient reported outcomes.
      Previous literature has established complication rates after DBT repair, however our study suggests a variability in this rate may be dependent on surgeon experience.
      • Dunphy T.R.
      • Hudson J.
      • Batech M.
      • Acevedo D.C.
      • Mirzayan R.
      Surgical treatment of distal biceps tendon ruptures: an analysis of complications in 784 surgical repairs.
      ,
      • Huynh T.
      • Leiter J.
      • MacDonald P.B.
      • Dubberley J.
      • Stranges G.
      • Old J.
      • et al.
      Outcomes and complications after repair of complete distal biceps tendon rupture with the cortical button technique.
      ,
      • Matzon J.L.
      • Graham J.G.
      • Penna S.
      • Ciccotti M.G.
      • Abboud J.A.
      • Lutsky K.F.
      • et al.
      A Prospective Evaluation of Early Postoperative Complications After Distal Biceps Tendon Repairs.
      Our data suggests that there is a complication based learning-curve occurring within the first 14-21 cases for early-career upper-extremity surgeons. The re-rupture rate reported in our investigation (5%) is consistent with prior published series and systematic reviews.
      • Huynh T.
      • Leiter J.
      • MacDonald P.B.
      • Dubberley J.
      • Stranges G.
      • Old J.
      • et al.
      Outcomes and complications after repair of complete distal biceps tendon rupture with the cortical button technique.
      ,
      • Ford S.E.
      • Andersen J.S.
      • Macknet D.M.
      • Connor P.M.
      • Loeffler B.J.
      • Gaston R.G.
      Major complications after distal biceps tendon repairs: retrospective cohort analysis of 970 cases
      ,
      • Matzon J.L.
      • Graham J.G.
      • Penna S.
      • Ciccotti M.G.
      • Abboud J.A.
      • Lutsky K.F.
      • et al.
      A Prospective Evaluation of Early Postoperative Complications After Distal Biceps Tendon Repairs.
      ,
      • Cain R.A.
      • Nydick J.A.
      • Stein M.I.
      • Williams B.D.
      • Polikandriotis J.A.
      • Hess A.V.
      Complications following distal biceps repair.
      ,
      • Dunphy T.R.
      • Hudson J.
      • Batech M.
      • Acevedo D.C.
      • Mirzayan R.
      Surgical treatment of distal biceps tendon ruptures: an analysis of complications in 784 surgical repairs.
      ,
      • Siebenlist S.
      • Schmitt A.
      • Imhoff A.B.
      • Lenich A.
      • Sandmann G.H.
      • Braun K.F.
      • et al.
      Intramedullary cortical button repair for distal biceps tendon rupture: a single-center experience.
      Historically, single-incision techniques have been associated with a higher rate of nerve injury (15% to 33%).
      • Baker B.E.
      • Bierwagen D.
      Rupture of the distal tendon of the biceps brachii. Operative versus non-operative treatment.
      ,
      • Meherin J.M.
      • Kilgore E.S.
      The treatment of ruptures of the distal bi-ceps brachii tendon.
      Review of current series reporting on sensory neuropraxia demonstrate a range from 12% to 42%.
      • Huynh T.
      • Leiter J.
      • MacDonald P.B.
      • Dubberley J.
      • Stranges G.
      • Old J.
      • et al.
      Outcomes and complications after repair of complete distal biceps tendon rupture with the cortical button technique.
      ,
      • Ford S.E.
      • Andersen J.S.
      • Macknet D.M.
      • Connor P.M.
      • Loeffler B.J.
      • Gaston R.G.
      Major complications after distal biceps tendon repairs: retrospective cohort analysis of 970 cases
      ,
      • Siebenlist S.
      • Schmitt A.
      • Imhoff A.B.
      • Lenich A.
      • Sandmann G.H.
      • Braun K.F.
      • et al.
      Intramedullary cortical button repair for distal biceps tendon rupture: a single-center experience.
      ,
      • Cain R.A.
      • Nydick J.A.
      • Stein M.I.
      • Williams B.D.
      • Polikandriotis J.A.
      • Hess A.V.
      Complications following distal biceps repair.
      ,
      • Dunphy T.R.
      • Hudson J.
      • Batech M.
      • Acevedo D.C.
      • Mirzayan R.
      Surgical treatment of distal biceps tendon ruptures: an analysis of complications in 784 surgical repairs.
      More recently Matzon et al performed a large prospective cohort study of DBT repairs with sixty-five patients (30.7%) had 73 complications.
      • Matzon J.L.
      • Graham J.G.
      • Penna S.
      • Ciccotti M.G.
      • Abboud J.A.
      • Lutsky K.F.
      • et al.
      A Prospective Evaluation of Early Postoperative Complications After Distal Biceps Tendon Repairs.
      Fifty patients (44.6%) in the 1-incision group experienced complications compared with 15 (15.0%) in the 2-incision group.
      • Matzon J.L.
      • Graham J.G.
      • Penna S.
      • Ciccotti M.G.
      • Abboud J.A.
      • Lutsky K.F.
      • et al.
      A Prospective Evaluation of Early Postoperative Complications After Distal Biceps Tendon Repairs.
      Overall, 57 patients (26.9%) had sensory neurapraxias.
      • Matzon J.L.
      • Graham J.G.
      • Penna S.
      • Ciccotti M.G.
      • Abboud J.A.
      • Lutsky K.F.
      • et al.
      A Prospective Evaluation of Early Postoperative Complications After Distal Biceps Tendon Repairs.
      Of the patients with neurapraxias, 94.7% were resolved or improving at the time of the latest follow-up. Sensory neuropraxia occurred in 27 patients (47%), 7 (39%) and 20 (51%) respectively for each surgeon in our study. In total 18 (32%) resolved and 9 (16%) remained unresolved at 6 months follow-up. When comparing complications within the first year and beyond 1 year of practice, we found no difference in these rates for each surgeon (5 (71%) vs 4 (36%) and 5 (83%) vs 16 (48%) respectively).
      The learning curve for operative time was 4 cases for both surgeons in our series. The consolidation phase, or time in which the surgeon is gaining proficiency in performance, varied from 13 to 32 cases for the two surgeons of our series. The mastery phase, where surgeon performance reaches a steady state, is suggested to occur after 18-36 cases for the two surgeons in our series. To our knowledge, this study is the first to report early surgeon performance with respect to DBT repairs. The CUSUM analysis has been supported as the standard method for reporting operative learning curves within orthopedics and other surgical specialties.
      • Steiner S.H.
      • Cook R.J.
      • Farewell V.T.
      • Treasure T.
      Monitoring surgical performance using risk-adjusted cumulative sum charts.
      ,
      • Sugishita T.
      • Tsukamoto S.
      • Imaizumi J.
      • Takamizawa Y.
      • Inoue M.
      • Moritani K.
      • et al.
      Evaluation of the learning curve for robot-assisted rectal surgery using the cumulative sum method.
      ,
      • Yap C.H.
      • Colson M.E.
      • Watters D.A.
      Cumulative sum techniques for surgeons: a brief review.
      In the upper extremity, Blaas et al supported a previously established operative learning curve of 15 cases for reverse total shoulder arthroplasty for patients with proximal humerus fractures.
      • Choi S.
      • Bae J.H.
      • Kwon Y.S.
      • Kang H.
      Clinical outcomes and complications of cementless reverse total shoulder arthroplasty during the early learning curve period.
      ,
      • Blaas L.S.
      • Yuan J.Z.
      • Lameijer C.M.
      • van de Ven P.M.
      • Bloemers F.W.
      • Derksen R.J.
      Surgical learning curve in reverse shoulder arthroplasty for proximal humerus fractures.
      In spine, a study by Yu et al reported a learning curve of 17-18 cases with respect to operative time for cases involving robot-assisted pedicle screw fixation while an operative time learning curve of 58 cases for the lumbar decompressive laminectomy using a biportal endoscopic approach was reported by Park et al.
      • Zhang L.
      • Sankaranarayanan G.
      • Arikatla V.S.
      • Ahn W.
      • Grosdemouge C.
      • Rideout J.M.
      • et al.
      Characterizing the learning curve of the VBLaST-PT©(virtual basic laparoscopic skill trainer).
      ,
      • Park S.M.
      • Kim H.J.
      • Kim G.U.
      • Choi M.H.
      • Chang B.S.
      • Lee C.K.
      • et al.
      Learning curve for lumbar decompressive laminectomy in biportal endoscopic spinal surgery using the cumulative summation test for learning curve.
      Beyond orthopedics, CUSUM-based operative learning curves have reported to be approximately 30 cases for robot assisted colorectal surgery, approximately 50 cases in surgical resection of advanced ovarian cancer, and 43 cases for robotic assisted transabdominal preperiotoneal repair of inguinal hernias.
      • Sugishita T.
      • Tsukamoto S.
      • Imaizumi J.
      • Takamizawa Y.
      • Inoue M.
      • Moritani K.
      • et al.
      Evaluation of the learning curve for robot-assisted rectal surgery using the cumulative sum method.
      ,
      • Nishikimi K.
      • Tate S.
      • Matsuoka A.
      • Shozu M.
      Learning curve of high-complexity surgery for advanced ovarian cancer.
      ,
      • Proietti F.
      • La Regina D.
      • Pini R.
      • Di Giuseppe M.
      • Cianfarani A.
      • Mongelli F.
      Learning curve of robotic-assisted transabdominal preperitoneal repair (rTAPP) for inguinal hernias.
      Notably, the CUSUM learning curve for operative time is shorter than complication rate for the two surgeons in our series while no learning curve for patient reported outcomes was reported.
      Our investigation has a number of limitations which should be considered. Many of these
      limitations are inherent to retrospective series, including the fact that complications may be underreported compared to prospective data collection. Of the 78 cases performed, 21 had <6 months of postoperative follow-up and were unable to be included in the assessment of PROMs. This study includes two surgeons and considering the small sample size of early career surgeons, it remains uncertain if these results are generalizable to a larger early career surgeon population. Surgeon 2 performed more than twice the number of cases as Surgeon 1 and the impact of these differing case numbers remains uncertain. This study lacked an internal control group consisting of experienced surgeons at our institution. This would have allowed for more robust comparisons to the early-career surgeons, as comparisons to prior published series is less ideal. However, the results of DBT repair have been extensively studied. This study included two surgeons in an academic practice, so it remains uncertain if these results are generalizable to other institutions or types of training. The surgeons utilized three fixation methods and small sub-group numbers would make meaningful comparisons between fixation methods difficult. There was no standardization of routine postop radiographs to evaluate for heterotopic ossification, incompletely evaluating this postoperative complication, although less likely in our cohort as only a single incision DBT repairs were performed in all cases. The small sample size does not allow for analysis of shorter time intervals to possibly elucidate changes in operative time and complications. We did not measure postoperative strength.

      CONCLUSION

      In summary, our data suggest a learning curve ranging between 4 cases and approximately 20 cases for operative times and complication rates respectively after DBT repair for upper-extremity surgeons at the beginning of their careers. Early-career surgeons appear to have acceptable clinical results and complications relative to previously published series irrespective of their learning stage.

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      • Zhang Q.
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