Smaller radioulnar window is associated with a distal biceps tendon rupture in patients with limited forearm rotation: a 3-dimensional computed tomography comparison study of proximal impingement caused by radial tuberosity hypertrophy-a single-center case series.

BACKGROUND: It has been suggested that hypertrophy of the radial tuberosity may result in impingement leading to either a lesion of the distal biceps tendon or rotational impairment. Two previous studies on hypertrophy of the radial tuberosity had contradictory results and did not examine the distance between the radius and ulna: the radioulnar window. Therefore, this comparative cohort study aimed to investigate the radioulnar window in healthy subjects and compare it with that in subjects with either nontraumatic-onset rotational impairment of the forearm or nontraumatic-onset distal biceps tendon ruptures with rotational impairment of the forearm by use of dynamic 3-dimensional computed tomography measurements to attain a comprehensive understanding of the underlying etiology of distal biceps tendon ruptures. We hypothesized that a smaller radioulnar window would increase the risk of having a nontraumatic-onset distal biceps tendon rupture and/or rotational impairment compared with healthy individuals. METHODS: This study measured the distance between the radius and ulna at the level of the radial tuberosity using entire-forearm computed tomography scans of 15 patients at the Amphia Hospital between 2019 and 2022. Measurements of healthy subjects were compared with those of subjects who had nontraumatic-onset rotational impairment of the forearm and subjects who had a nontraumatic-onset distal biceps tendon rupture with rotational impairment of the forearm. The Wilcoxon signed rank test was used for individual comparisons, and the Mann-Whitney U test was used for group comparisons. RESULTS: A significant difference was found between the radioulnar window in the forearms of the subjects with a distal biceps tendon rupture (mean, 1.6 mm; standard deviation 0.2 mm) and the radioulnar window in the forearms of the healthy subjects (mean, 4.8 mm; standard deviation, 1.4 mm; P = .018). A trend toward smaller radioulnar windows in the rotational impairment groups was also observed, although it was not significant (P > .05). CONCLUSIONS: The radioulnar window in the forearms of the subjects with a distal biceps tendon rupture with rotational impairment was significantly smaller than that in the forearms of the healthy subjects. Therefore, patients with a smaller radioulnar window have a higher risk of rupturing the distal biceps tendon. Nontraumatic-onset rotational impairment of the forearm may also be caused by a similar mechanism. Future studies are needed to further evaluate these findings.

Distal biceps tendon repair using a double intracortical button anatomic footprint repair technique.

INTRODUCTION: Distal biceps tendon repair is usually performed via a double-incision or single-incision bicortical drilling technique. However, these techniques are associated with specific complications and usually do not allow for anatomic footprint restoration. It was the aim of this study to report the clinical results of a double intracortical button anatomic footprint repair technique for distal biceps tendon tears. We hypothesized that this technique would result in supination strength comparable to the uninjured side with a low rerupture rate and minimal bony or neurologic complications. MATERIAL AND METHODS: This was a retrospective, single-surgeon cohort study of a consecutive series of 22 patients with a mean (standard deviation) age of 50.7 (9.4) years and at least 1-year follow-up after distal biceps tendon repair. At final follow-up, complications, range of motion (ROM), the Patient-rated Elbow Evaluation (PREE), Mayo Elbow Performance Score (MEPS), Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire, visual analog scale (VAS) for pain, patient satisfaction, and supination strength in neutral as well as 60° of supination were analyzed. Radiographic evaluation was performed on a computed tomography scan. RESULTS: One patient (4.5%) experienced slight paresthesia in the area of the lateral antebrachial cutaneous nerve. Heterotopic ossification was seen in 1 patient (4.5%). All patients recovered full ROM except for 1 who had 10° of loss of flexion and extension. Median PREE score was 4.6 (0-39.6), median MEP was 100 (70-100), and median DASH score was 1.4 (0-16.7). All but 1 patient were very satisfied with the outcome. The affected arm had a mean of 98% (±13%) of neutral supination strength (P = .633) and 94% (±12%) of supination strength in 60° (P = .054) compared with the contralateral, unaffected side. There were 4 cases (18.2%) of cortical thinning due to at least 1 button and 1 case of button pullout (4.5%). CONCLUSIONS: The double intracortical button anatomic footprint repair technique seems to provide reliable restoration of supination strength and excellent patient satisfaction while minimizing complications, particularly nerve damage and heterotopic ossification.

Distal biceps tendon repair: outcome and complications with single incision anchor fixation.

PURPOSE: The purpose of this study is to evaluate the functional outcome and quality of life in distal biceps tendon repair with single incision technique and anchor fixation method. METHODS: A retrospective cohort study was made of patients with complete distal biceps tendon rupture. The chosen repair method was single incision technique with anchor fixation. The outcome was assessed with functional testing of the elbow with strength and ROM. Additionally Mayo elbow performance index, Oxford elbow score, Disability arm hand shoulder questionnaire and patient rated elbow evaluation scores were used to evaluate quality of life. RESULTS: Of the 28 patients, the average strength in flexion and supination was decreased with 91% and 89% of the strength compared to the non-injured arm. ROM was preserved in flexion, extension, supination and pronation. The mean scores for quality of life evaluation were MEPS = 96 ± 7.8, OES = 46.8 ± 1.9, DASH = 1.0 ± 1.9 and PREE = 2.0 ± 3.6. LABCN injury was the most common temporary complication with 30% followed by pain with 23%. Two patients were identified with HO and 1 patient was identified with median nerve injury. There were no cases of radioulnar synostosis and PIN injury. CONCLUSION: Overall strength in flexion and supination were slightly decreased with preserved ROM. Patients reported nearly perfect quality of life as demonstrated with the scores. The complications rate was high with mainly minor complications. Distal biceps tendon repair with single incision technique and anchor fixation overall leads to a very satisfying outcome.

Reliability and Validity of the Hook Test for Diagnosis of Distal Biceps Tendon Ruptures.

PURPOSE: Although the initial description of the distal biceps tendon (DBT) hook test (HT) reported 100% sensitivity (Sn) and specificity (Sp), subsequent retrospective series have demonstrated imperfect validity. The purpose of this investigation was to prospectively assess the validity and reliability of the HT for complete DBT ruptures. We aimed to determine the Sn/Sp and interrater reliability for the HT. METHODS: A consecutive series of adult patients presenting to our outpatient clinics with an elbow complaint was prospectively examined. Patients were included if they had undergone advanced imaging (magnetic resonance imaging or ultrasound) that imaged the DBT and underwent DBT repair. There were four participating surgeons, all of whom were blinded to magnetic resonance imaging/ultrasound prior to performing the HT. To determine the Sn/Sp of the HT and advanced imaging, intraoperative findings served as the primary reference standard. The interrater reliability of the HT was calculated for cases in which a primary examiner (surgeon) and secondary examiner (physician assistant or resident) performed the HT. RESULTS: Of 64 patients who had undergone advanced imaging, 28 (44%) underwent DBT surgery and were included in the assessment of Sn/Sp. The mean age was 49 years, and all patients were men. The Sn and Sp of the HT were 96% and 67%, respectively. Advanced imaging demonstrated 100% Sn and Sp. Twenty-five patients were evaluated by a primary and secondary examiner. The interrater reliability was substantial (Cohen kappa, 0.71). CONCLUSIONS: The Sn and Sp of the HT were 96% and 67%, respectively, when assessed prospectively. Advanced imaging findings (magnetic resonance imaging/ultrasound) demonstrated 100% Sn and Sp. The HT can be performed reliably by examiners with varying experience levels. Considering the imperfect validity of the HT, we caution against the use of this examination alone to diagnose DBT ruptures. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic II.

The use of prescription testosterone is associated with an increased likelihood of experiencing a distal biceps tendon injury and subsequently requiring surgical repair.

BACKGROUND: In the United States, the use of testosterone therapy has increased over recent years. Anabolic steroid use has been associated with tendon rupture, although there is a paucity of evidence evaluating the risk of biceps tendon injury (BTI) with testosterone therapy. The aim of this study was to quantify the risk of BTI after the initiation of testosterone therapy. METHODS: This was a retrospective cohort study using the PearlDiver database. Records between 2011 and 2018 were queried to identify patients aged 35-75 years who filled a testosterone prescription for a minimum of 3 months. A control group was created, comprising patients aged 35-75 years who had never filled a prescription for exogenous testosterone. International Classification of Diseases, Ninth Revision, International Classification of Diseases, Tenth Revision, and Current Procedural Terminology codes were used to identify patients with distal biceps injuries and those undergoing surgical repair. Three matching processes were completed: one for the overall cohort, one for the cohort comprising only male patients, and one for the cohort comprising only female patients. Each cohort was matched to its control on age, sex, Charlson Comorbidity Index, diabetes, tobacco use, and osteoporosis. Multivariate logistic regression was used to compare rates of distal BTI and subsequent surgical repair in the testosterone groups with their control groups. RESULTS: A total of 776,974 patients had filled a prescription for testosterone for a minimum of 3 consecutive months. In the overall matched analysis between the testosterone and control groups (n = 291,610 in both), the mean age of the patients was 53.9 years and 23.1% were women. Within 1 year of filling exogenous testosterone prescriptions for a minimum of 3 consecutive months, 650 patients experienced a distal BTI compared with 159 patients in the control group (odds ratio [OR], 4.10; 95% confidence interval [CI], 3.45-4.89; P < .001). At any time after testosterone therapy, patients with testosterone use were more than twice as likely to experience a distal BTI as their matched controls (OR, 2.07; 95% CI, 1.94-2.38). Patients who filled prescriptions for testosterone were more likely to undergo surgical repair within a year of the injury compared with the control group. A similar trend was seen in the cohort comprising male patients (OR, 1.63; 95% CI, 1.29-2.07). CONCLUSION: Patients with prior prescription testosterone exposure have an increased rate of BTI and biceps tendon repair compared with patients without such exposure. This finding provides insight into the risk profile of testosterone therapy, and doctors should consider counseling patients about this risk, particularly male patients.

Avoiding the posterior interosseous nerve during 2-incision distal biceps tendon repair: an anatomic study.

BACKGROUND: The posterior interosseous nerve (PIN) is the most commonly injured motor nerve during distal biceps tendon repair resulting in severe functional deficits. Anatomic studies of distal biceps tendon repairs have evaluated the proximity of the PIN to the anterior radial shaft in supination, but limited studies have evaluated the location of the PIN in relation to the radial tuberosity (RT), and none have examined its relation to the subcutaneous border of the ulna (SBU) with varying forearm rotation. This study evaluates the location of the PIN in relation to the RT and SBU to help guide surgeons in safe placement of the dorsal incision and the safest zones of dissection. METHODS: The PIN was dissected from arcade of Frohse to 2 cm distal to the RT in 18 cadaver specimens. Four lines were drawn perpendicular to the radial shaft at the proximal, middle, and distal aspect of and 1 cm distal to the RT in the lateral view. Measurements were recorded with a digital caliper along these lines to quantify the distance between the SBU and RT to the PIN with the forearm in neutral, supination, and pronation with the elbow at 90° flexion. Measurements were also made along the length of the radius at the volar, middle, and dorsal surfaces at the distal aspect of the RT to assess its proximity to the PIN. RESULTS: Mean distances to the PIN were greater in pronation than supination and neutral. The PIN crossed the volar surface of the distal aspect of the RT -6.9 ± 4.3 mm (-13, -3.0) in supination, -0.4 ± 5.8 mm (-9.9, 2.5) in neutral, and 8.5 ± 9.9 mm (-2.7, 13) in pronation. One centimeter distal to the RT, mean distance to the PIN was 0.54 ± 4.3 mm (-4.5, 8.8) in supination, 8.5 ± 3.1 mm (3.2, 14) in neutral, and 10 ± 2.7 mm (4.9, 16) in pronation. In pronation, mean distances from the SBU to the PIN at points A, B, C, and D were 41.3 ± 4.2, 38.1 ± 4.4, 34.9 ± 4.2, and 30.8 ± 3.9 mm, respectively. CONCLUSION: PIN location is quite variable, and to avoid iatrogenic injury during 2-incision distal biceps tendon repair, we recommend placement of the dorsal incision no more than 25 mm anterior to the SBU and carrying out deep dissection proximally first to identify the RT before continuing the dissection distally to expose the tendon footprint. The PIN was at risk of injury along the volar surface at the distal aspect of the RT in 50% with neutral rotation and 17% with full pronation.

Ultrasound Assessment of an Isolated Rupture of the Medial Bundle of a Bifid Distal Biceps Tendon.

This case study describes a patient with a clinically ruptured distal biceps tendon, with ultrasound detecting an isolated rupture of the medial bundle of a bifid distal biceps tendon. A 45-year-old male presented to the accident and emergency department with a week-old history of a right elbow injury. The ultrasound scan demonstrated a hypoechoic, corrugated distal biceps tendon with a tendon stump close to the radial tuberosity insertion in keeping with a rupture. However, a small caliber accessory or bifid distal biceps tendon was also identified and was intact. Typically, distal biceps tendon ruptures occur following a traumatic event with most detected clinically although imaging is required to confirm the diagnosis. Ultrasound is utilized to assess these injuries, and several different techniques or approaches are described in the literature. A combination of these approaches is required to make an accurate diagnosis. Detection of bifid distal biceps tendons is important for patient management, especially if a surgical repair is considered. This case highlights the anatomical variant of a bifid distal biceps tendon, which was ruptured clinically. The ultrasound diagnosis of distal biceps tendon ruptures can be challenging, especially when there is limited tendon retraction. This case also demonstrated the importance of dynamic ultrasound in the assessment of tendon ruptures.

Bicortical suspensory button fixation yields greater ultimate load to failure over unicortical all-suture anchor fixation in distal biceps brachii tendon repair.

BACKGROUND: Various distal biceps tendon repair techniques exist, each with their own biomechanical profile. Recently, all-suture anchor fixation has recently become an intriguing option for distal biceps fixation, compared with the proven track record of the suspensory cortical button. In addition, intramedullary techniques have been utilized as a means to avoid complications such as nerve damage seen with extramedullary fixation. PURPOSE: The purpose of this study is to perform a comparative biomechanical analysis of 4 unique distal biceps tendon fixation methods: Unicortical/intramedullary all-suture anchor fixation (UIAS), Bicortical/extramedullary all-suture anchor fixation (BEAS), Unicortical/intramedullary suspensory button fixation (UISB), and Bicortical/extramedullary suspensory button fixation (BESB). STUDY DESIGN: Controlled Laboratory study. METHODS: 24 fresh-frozen cadaveric elbows were randomized into 4 groups providing data from 6 specimens, with each group undergoing a different repair technique. The specimens underwent 2 studies: Cyclic loading and Ultimate Load to failure (ULTF) testing. The repaired elbows were cycled 3000 times between 0 and 90 degrees of flexion, with displacement under cyclic loading at the repair site measured using a differential variable reductance transducer. ULTF test was performed with the elbow flexed at 90 degrees. The modes of failure were recorded. RESULTS: The mean cyclic displacements between the 4 groups were as follows: UIAS: 1.45 ± 1.04 mm; BEAS: 2.75 ± 1.32 mm; UISB: 1.45 ± .776 mm; BESB: 2.66 ± 1.18 mm (p= 0.077). Bicortical repairs displayed greater displacement after cyclic loading when compared with unicortical repairs regardless of anchor used (p= 0.007). The mean ULTF for each group was as follows: all-suture intramedullary: 200 N; all-suture extramedullary: 330 N; cortical-button intramedullary: 256 N; cortical-button extramedullary: 342 N). All-suture unicortical/intramedullary repair had a significantly lower ULTF (200 N) compared with cortical-button Bicortical/extramedullary repair (342 N) (p=0.043). CONCLUSION: Bicortical/extramedullary suspensory button fixation demonstrated a greater ultimate load to failure when compared with unicortical/intramedullary all-suture anchor fixation. These findings suggest that bicortical/extramedullary suspensory cortical button fixation is a biomechanically superior construct as compared to unicortical/intramedullary all-suture anchor fixation. However, there was no significant difference in ULTF between extra-medullary, Bicortical button or Bicortical, all-suture anchor fixation.

Three weeks of indomethacin is not superior to 1 week of meloxicam as prophylaxis for heterotopic ossifications after distal biceps tendon repair with a single-incision technique.

BACKGROUND: The aim of this study was to assess the efficacy of 3 weeks of indomethacin, a nonselective nonsteroidal anti-inflammatory drug, in comparison to 1 week of meloxicam as prophylaxis for heterotopic ossifications (HOs) after distal biceps tendon repair. METHODS: A single-center retrospective study was performed on 78 patients undergoing distal biceps tendon repair between 2008 and 2019. From 2008 to 2016, patients received meloxicam 15 mg daily for the period of 1 week as usual care. From 2016 onward, the standard protocol was changed to indomethacin 25 mg 3 times daily for 3 weeks. All patients underwent a single-incision repair with a cortical button technique. The postoperative rehabilitation protocol was similar for all patients. The postoperative radiographs at 8-week follow-up were assessed blindly by 7 independent assessors. If HOs were present, it was classified according to the Ilahi-Gabel classification for size and according to the Gärtner-Heyer classification for density. Statistical analysis was performed to analyze the difference in HO between the patients who were treated with indomethacin and with meloxicam. RESULTS: Seventy-eight patients, with a mean age of 48.8 years (range 30-72) were included. The mean follow-up after surgery was 12 months (range 2-45). Indomethacin (21 days, 25 mg 3 times per day) was prescribed to 26 (33%) patients. The 52 other patients (67%) were prescribed meloxicam 15 mg daily for 7 days. HOs were seen in 19 patients 8 weeks postoperatively. Five of 26 patients treated with indomethacin developed HO, and 14 of 52 patients treated with meloxicam developed HO (P = .5). Two patients had symptomatic HO with minor restrictions in movement; neither patient was treated with indomethacin. Significantly more HOs were seen in patients with a longer time from injury to surgery (P = .01) The intraclass correlation score for reliability between assessors for HO scoring on postoperative radiographs was good to excellent for both classifications. CONCLUSION: In this study, HOs were seen in 24% of postoperative radiographs. Three weeks of indomethacin was not superior to meloxicam for 1 week for the prevention of HO after single-incision distal biceps tendon repair.

Systematic review of distal biceps tendon rupture in athletes: treatment and rehabilitation.

BACKGROUND: Distal biceps tendon rupture is a rare injury associated with decreased elbow flexion and forearm supination strength. This impairment is not tolerated by high-demand patients like athletes. PURPOSE: To review treatment and rehabilitation applied to injured athletes and study their impact in return to sports. METHODS: MEDLINE, Cochrane, Web of Science, and Scopus online databases were searched. A systematic review was conducted using the PRISMA guidelines; studies published on distal biceps tendon rupture treatment and rehabilitation of athletes until June 30, 2021, were identified. A quantitative synthesis of factor related to return to preinjury sport activity was made. RESULTS: Ten articles were identified, including 157 athletes. Mean age was 40.5 years, and the dominant arm was injured in 103 cases (66%). Rupture was acute in 121 athletes (77%), and the mean follow-up was 25.7 months. A hundred and fifty-three athletes (97.5%) successfully returned to sport within a mean time of 6.2 months. Surgical treatment was followed in all cases. One-incision technique was chosen in 115 (73%) and suture anchor fixation in 52 (33%) cases. No postsurgical immobilization was reported in 38 (24%) and immobilization for 2 weeks in 124 (79%) athletes. Decreased supination-pronation and flexion-extension arc was found in 63 (40%) and 27 (17%) cases, respectively. Earlier return to sport was associated with nondominant-side (P = .007) and acute (P < .001) injuries, participation in weightlifting (P = .001), double-incision approach (P = .005), cortical button fixation (P < .001), and absence of supination-pronation restriction (P = .032). Time of return to sport activity was independent of rehabilitation, including immobilization (P = .539) and strengthening (P = .155), and decreased flexion-extension arc (P = .059). CONCLUSION: Athletes sustaining distal biceps tendon rupture have a high postoperative return to sport rate, independently of selected surgical technique or rehabilitation program. However, a relation between the surgical technique and time of return to sport was found. Rehabilitation did not influence time of return to sport.

Operative vs. nonoperative treatment of distal biceps ruptures: a systematic review and meta-analysis.

BACKGROUND AND HYPOTHESIS: Ruptures of the distal biceps tendon are most commonly due to traumatic eccentric loading in the middle-aged male population and can result in functional deficits. Although surgical repair has been demonstrated to result in excellent outcomes, there are few comparative studies that show clear functional benefits over nonoperative management. The aim of this systematic review and meta-analysis is to compare the functional outcomes of operative and nonoperative management for these injuries. We hypothesized that operative treatment would be associated with significantly superior outcomes. METHODS: According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic review of the literature was performed using MEDLINE, SPORTDiscus, CINAHL (Cumulative Index to Nursing and Allied Health Literature), CENTRAL (Cochrane Central Registry of Controlled Trials), Embase, and Web of Science databases. Outcomes of interest included range of motion (ROM), strength, endurance, and patient-reported outcomes including Disabilities of the Arm, Shoulder and Hand (DASH), Mayo Elbow Performance Score (MEPS), and visual analog scale (VAS) for pain scores. Summary effect estimates of the mean difference between operative and nonoperative management for each outcome were estimated in mixed effects models. RESULTS: Of an initially identified 6478 studies, 62 reported outcomes for a total of 2481 cases (2402 operative, 79 nonoperative), with an overall average age of 47.4 years (47.3 for operative, 50.3 for nonoperative). There were 2273 (98.5%) males and 35 (1.5%) females among operative cases, whereas all 79 (100%) nonoperative cases were males. Operative management was associated with a significantly higher flexion strength (mean difference, 25.67%; P < .0001), supination strength (mean difference, 27.56%; P < .0001), flexion endurance (mean difference, 11.12%; P = .0268), and supination endurance (mean difference, 33.86%; P < .0001). Patient-reported DASH and MEPS were also significantly superior in patients who underwent surgical repair, with mean differences of -7.81 (P < .0001) and 7.41 (P = .0224), respectively. Comparative analyses for ROM and pain VAS were not performed because of limited reporting in the literature for nonoperative management. CONCLUSION: This study represents the first systematic review and meta-analysis to compare functional and clinical outcomes following operative and nonoperative treatment of distal biceps tendon ruptures. Operative treatment resulted in superior elbow and forearm strength and endurance, as well as superior DASH and MEPS.

Anatomic factors associated with partial distal biceps tendon tears: a comparative control study.

BACKGROUND: There is minimal literature on the anatomic factors associated with partial distal biceps tendon (DBT) tears. It has been proposed that a larger radial tuberosity size-and, therefore, a smaller radioulnar space during pronation-may cause mechanical impingement of the DBT predisposing to tears. We sought to investigate the anatomic factors that may be associated with partial DBT tears by retrospectively reviewing the DBT anatomy using 3-T magnetic resonance imaging (MRI) scans of elbows with partial DBT tears and a comparison group of normal elbows. METHODS: Two independent observers retrospectively reviewed 3-T MRI scans of elbows with partial DBT tears and elbows without visible pathology. Basic demographic data were collected, and measurements of radial tuberosity length, radial tuberosity thickness, radioulnar space, and radial tuberosity-ulnar space were made using simultaneous tracker lines and a standardized technique. The ratio of radial tuberosity thickness to radial diameter and the ratio of radioulnar space to radial tuberosity-ulnar space were calculated. The presence or absence of enthesophytes and the presence of a single DBT vs. double DBTs were noted. RESULTS: This study included twenty-six 3-T MRI scans of 26 elbows with partial DBT tears and thirty 3-T MRI scans of 30 elbows without pathology. Basic demographic data were comparable between the 2 groups. The tear group showed statistically significantly larger mean measurements for radial tuberosity length (24.3 mm vs. 21.3 mm, P = .002) and radial tuberosity thickness (5.5 mm vs. 3.7 mm, P < .0001). The tear group also showed statistically significantly smaller measurements for radioulnar space (8.2 mm vs. 10.0 mm, P = .010) and radial tuberosity-ulnar space (7.2 mm vs. 9.1 mm, P = .013). The ratio of radial tuberosity thickness to radial diameter was statistically significantly larger in the tear group (0.389 vs. 0.267, P < .0001). There was a statistically significant positive correlation between partial DBT tears and the presence of enthesophytes (P = .007), as well as between partial DBT tears and the presence of 2 discrete DBTs rather than a single tendon or 2 DBTs that interdigitated prior to insertion (P < .0001). CONCLUSION: Larger radial tuberosities and smaller radioulnar and radial tuberosity-ulnar spaces are associated with partial DBT tears. Larger tuberosities and a smaller functional space for the DBT may lead to chronic impingement, tendon delamination, and consequent weakness, which ultimately lead to tears. Enthesophytes may be associated with tears for the same reason. The presence of 2 discrete DBTs that do not interdigitate prior to insertion is also associated with partial tears. This study will help clinicians understand the pathogenesis of partial DBT tears.

Anatomy of the distal biceps tendon: an in vivo 3-T magnetic resonance imaging study.

BACKGROUND: On the basis of the current literature, the optimal surgical technique for distal biceps tendon tears remains controversial. Cadaveric studies have investigated distal biceps anatomy but are limited by cohort size and tissue factors. We sought to investigate distal biceps anatomy in vivo by retrospectively reviewing magnetic resonance imaging (MRI) scans. An improved understanding of the anatomy of the distal biceps tendon will lead to better definition of the optimal anatomic surgical repair. METHODS: Two independent observers retrospectively reviewed 3-T MRI scans of elbows. Basic demographic data were collected, and measurements of tendon length, footprint width, footprint length, and footprint angle were taken using simultaneous tracker lines and a standardized technique. From the biceps muscle belly distally, the presence of a single tendon or double tendons was recorded and the tendon interdigitation point was measured if relevant. RESULTS: A total of 106 3-T MRI scans of 106 elbows of 103 patients were included. There were 71 male and 32 female patients, and the mean age was 44.7 years. Most distal biceps tendons exited the biceps muscle belly as separate entities (91%, 96 of 106 elbows) and then coalesced prior to insertion on the radial tuberosity (91%, 87 of 96 elbows). There was a positive correlation between tendon length and footprint length (P < .05), as well as between tendon length and footprint width (P < .05). The mean tendon length was 65.2 mm (95% confidence interval [CI], 63.3-66.8 mm; range, 44.3-86.8 mm), the mean distance from the musculotendinous junction to the interdigitation point was 38.3 mm (95% CI, 35.8-40.9 mm; range, 8.9-64.8 mm), the mean footprint width was 10.3 mm (95% CI, 9.9-10.7 mm; range, 5.9-16.3 mm), the mean footprint length was 16.2 mm (95% CI, 15.6-16.9; range, 7.3-25.4 mm), and the mean footprint angle was 32.1° (95% CI, 29.5°-34.6°; range, 8.5°-84.3°). CONCLUSION: An in vivo, high-resolution study of the anatomy of the distal biceps tendon improves our understanding of its complex morphology and hence our ability to perform an anatomic "footprint repair."

Acute distal biceps tendon rupture: retrospective analysis of two different approaches and fixation techniques.

PURPOSE: The aim of our study is to compare the modified double incision (DI) with bone tunnel reinsertion with the single-incision (SI) double tension slide technique in terms of clinical and functional outcomes and complication rates. METHODS: A retrospective comparative analysis was performed on 65 patients treated for total distal biceps tendon rupture. The surgical technique adopted for each patient was based on the preference of two experienced elbow surgeons. The DASH and MAYO questionnaires, functional outcome and ROM were recorded in all subjects. RESULTS: Of 65 patients, we collected data of a cohort of 54 distal biceps tendon ruptures that satisfied inclusion criteria. Twenty-five were treated by modified DI and 29 SI techniques. The recovery of the complete ROM in terms of flexion/extension and prono-supination occurred in the 79.6% of the patients, without statistical significant difference between the adopted technique. We reported a complication rate of 12% and 20.7% for DI and SI techniques, respectively, without statistical correlation (P = 0.84). The average DASH score was similar for DI and SI techniques without significant differences (P = 0,848). The Mayo score results were excellent in the majority of the patients. No significant difference in MAYO results was reported comparing the surgical techniques (P = 1). CONCLUSION: Both techniques provide a reliable and strong repair with an optimal recovery of ROM returning to preinjury activity with substantially overlapping timelines.

MRI findings of chronic distal tendon biceps reconstruction and associated post-operative findings.

Rupture of the distal biceps tendon is becoming increasingly diagnosed due to an active aging population and an increase in diagnostic imaging opportunities. While physical exam may help in diagnosis, magnetic resonance imaging (MRI) is particularly useful in evaluating chronic rupture. Although partial tears can be managed conservatively, the gold standard treatment for a chronic distal biceps tear is anatomic reinsertion with additional use of an allograft or autograft. No study has highlighted the normal appearance and postsurgical complications seen on MRI associated with allograft or autograft usage. Clinicians and radiologists may be unaware of the normal and abnormal post-operative imaging findings and their clinical relevance. The purpose of this manuscript is to discuss the epidemiology, clinical presentation, and preoperative MRI findings of distal biceps ruptures necessitating reconstruction, to explain distal biceps tendon surgical reconstruction technique with allograft or autograft usage, to display the normal and abnormal post-operative MRI findings, and to review the clinical outcomes associated with the procedure.

Greater radial tuberosity size is associated with distal biceps tendon rupture: a quantitative 3-D CT case-control study.

PURPOSE: During pronation, the distal biceps tendon and radial tuberosity internally rotate into the radioulnar space, reducing the linear distance between the radius and ulna by approximately 50%. This leaves a small space for the distal biceps tendon to move in and could possibly cause mechanical impingement or rubbing of the distal biceps tendon. Hypertrophy of the radial tuberosity potentially increases the risk of mechanical impingement of the distal biceps tendon. The purpose of our study was to determine if radial tuberosity size is associated with rupturing of the distal biceps tendon. METHODS: Nine patients with a distal biceps tendon rupture who underwent CT were matched 1:2 to controls without distal biceps pathology. A quantitative 3-dimensional CT technique was used to calculate the following radial tuberosity characteristics: 1) volume in mm3, 2) surface area in mm2, 3) maximum height in mm and 4) location (distance in mm from the articular surface of the radial head). RESULTS: Analysis of the 3-dimensional radial tuberosity CT-models showed larger radial tuberosity volume and maximum height in the distal biceps tendon rupture group compared to the control group. Mean radial tuberosity volume in the rupture-group was 705 mm3 (SD: 222 mm3) compared to 541 mm3 (SD: 184 mm3) in the control group (p = 0.033). Mean radial tuberosity maximum height in the rupture-group was 4.6 mm (SD: 0.9 mm) compared to 3.7 mm (SD: 1.1 mm) in the control group, respectively (p = 0.011). There was no statistically significant difference in radial tuberosity surface area (ns) and radial tuberosity location (ns). CONCLUSION: Radial tuberosity volume and maximum height were significantly greater in patients with distal biceps tendon ruptures compared to matched controls without distal biceps tendon pathology. This supports the theory that hypertrophy of the radial tuberosity plays a role in developing distal biceps tendon pathology. LEVEL OF EVIDENCE: Level III.

No functional differences in anatomic reconstruction with one vs. two suture anchors after non-simultaneous bilateral distal biceps brachii tendon rupture: a case report and review of the literature.

BACKGROUND: Surgical reattachment of the tendon is still the gold standard for ruptures of the distal biceps brachii tendon. Several fixation techniques have been described in the literature, with suture anchors being one of the most common fixation techniques. Currently, there is no data available on how many anchors are required for a safe and stable refixation. In this case report clinical data of a patient with non-simultaneous bilateral distal biceps tendon ruptures treated with a different number of suture anchors for each side (one vs. two) are demonstrated. CASE PRESENTATION: A 47-year-old factory worker suffered a rupture of the distal biceps tendon on both arms following two different occasions. The left side was fixed using a single suture anchor, while refixation on the right side was performed with two anchors. The patient was prospectively followed for one year. Functional outcome was assessed using the Andrews Carson Score (ACS), the Oxford Elbow Score (OES), and the Disabilities of Arm, Shoulder and Hand (DASH) Score after six, twelve, 24 and 48 weeks. Furthermore, an isokinetic strength measurement for flexion strength was performed after 24 and 48 weeks. After 48 weeks the patient presented with excellent functional outcome scores and no follow-up complications. During the follow-up period, no differences in the functional scores nor in the isokinetic flexion strength measurement could be detected. Furthermore, no radiological complications (like heterotopic ossifications) could be detected in the postoperative radiographs after one year. CONCLUSIONS: Anatomic reattachment of the distal biceps tendon is a successful operative treatment option for distal biceps tendon ruptures. Suture anchor fixation remains one of the most common techniques, as it allows fast surgery and provides good results with respect to range of motion (ROM) and functional scoring according to the current literature. However, the number of anchors required for a stable fixation remains unclear. As indicated by our presented case, we hypothesize, that there are no significant differences between a one-point or a two-point fixation. In the presented case report, no intraindividual differences between the usage of one versus two suture anchors were evident in the short-term follow-up.

An intact lacertus fibrosus improves strength after reinsertion of the distal biceps tendon.

PURPOSE: The importance of an intact lacertus fibrosus in distal biceps tendon injury is uncertain. This study aimed to assess long-term outcome following distal biceps tendon repair with focus on the significance of the lacertus fibrosus. METHODS: Thirty-six patients surgically treated for primary distal biceps tendon rupture were identified. Medical records were reviewed for patient demographics in addition to surgery-related data. All patients underwent a targeted clinical examination to assess elbow function and they completed a patient reported questionnaire. Radiographs were obtained at time of follow-up and evaluated for the presence of osteoarthritis (OA) and heterotopic ossification (HO). RESULTS: All patients were male. Median age at injury was 48 years (34-69) and median time of follow-up of was 71 months (23-165). All patients presented functional range of motion in the elbow. Median flexion strength was 76 Nm (45-135) (median 99% of uninjured side; range 66-128) with intact lacertus fibrosus and 70 Nm (43-124) (88%, 62-114) with torn lacertus fibrosus. Median supination strength was 6 Nm (3-11) (86%, range 36-144) with intact lacertus fibrosus and 8 Nm (3-17) (67%, 28-118) with torn lacertus fibrosus. No signs of OA were revealed, but three patients had major HO of which one patient had minor limitations in range of elbow motion. CONCLUSION: An intact lacertus fibrosus contributes to elbow strength and should be preserved in distal biceps tendon repair. LEVEL OF EVIDENCE: III.

Diagnosis, Etiology and Outcomes of Revision Distal Biceps Tendon Reattachment.

PURPOSE: To evaluate the incidence, etiology, and clinical outcomes after revision distal biceps tendon repair. We hypothesized that re-ruptures are rare and can be reattached with satisfactory results. METHODS: Cases were identified from the case log of the senior author. Demographic information, details regarding the primary repair and subsequent injury, time between reinjury and reattachment, and operative findings were recorded. Clinical outcomes were assessed using the Disabilities of the Arm, Shoulder, and Hand (DASH) and American Shoulder and Elbow Surgeons-Elbow (ASES-E) functional outcome scoring systems. Range of motion, strength, and ability to return to work were recorded. RESULTS: We identified 10 patients with re-rupture, all of whom were men. Average age was 46 years (range, 35-57 years). Four ruptures occurred in the dominant arm. Three patients had a history of bilateral ruptures. Incidence of primary failure was 1.1%. In 6 patients, re-rupture occurred 6 days to 11 months after the primary surgery. Three patients described a sense of ripping or tearing after a specific traumatic event. Four others had persistent pain after the primary reattachment. Re-rupture resulted from the loss of fixation owing to technical error, the suture pulling out from the tendon, or suture breakage. Two patients required an allograft. The hook test was abnormal in 3 patients. Magnetic resonance imaging results did not affect the operative plan. Nine patients returned to their former occupation. Five returned for follow-up evaluation and completion of the DASH and ASES-E self-assessment examinations. Average DASH score was 4.4 (range, 0-19) and average ASES-E was 93.2 (range, 74-100). Postoperative average elbow flexion was 141° (range, 135° to 145°), elbow extension was -12° (range, -5° to -30°), pronation was 70°, and supination was 80°. Postoperative average supination strength was 87.8% of the nonsurgical arm (range, 79% to 106%); average pronation strength was 79.2% of the nonsurgical arm (range, 50% to 110%). CONCLUSIONS: Revision reattachment resulted in acceptable functional outcomes. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Pressure Distribution to the Distal Biceps Tendon at the Radial Tuberosity: A Biomechanical Study.

PURPOSE: Mechanical impingement at the narrow radioulnar space of the tuberosity is believed to be an etiological factor in the injury of the distal biceps tendon. The aim of the study was to compare the pressure distribution at the proximal radioulnar space between 2 fixation techniques and the intact state. METHODS: Six right arms and 6 left arms from 5 female and 6 male frozen specimens were used for this study. A pressure transducer was introduced at the height of the radial tuberosity with the intact distal biceps tendon and after 2 fixation methods: the suture-anchor and the cortical button technique. The force (N), maximum pressure (kPa) applied to the radial tuberosity, and the contact area (mm2) of the radial tuberosity with the ulna were measured and differences from the intact tendon were detected from 60° supination to 60° pronation in 15° increments with the elbow in full extension and in 45° and 90° flexion of the elbow. RESULTS: With the distal biceps tendon intact, the pressures during pronation were similar regardless of extension and flexion and were the highest at 60° pronation with 90° elbow flexion (23.3 ± 53.5 kPa). After repair of the tendon, the mean peak pressure, contact area, and total force showed an increase regardless of the fixation technique. Highest peak pressures were found using the cortical button technique at 45° flexion of the elbow and 60° pronation. These differences were significantly different from the intact tendon. The contact area was significantly larger in full extension and 15°, 30°, and 60° pronation using the cortical button technique. CONCLUSIONS: Pressures on the distal biceps tendon at the radial tuberosity increase during pronation, especially after repair of the tendon. CLINICAL RELEVANCE: Mechanical impingement could play a role in both the etiology of primary distal biceps tendon ruptures and the complications occurring after fixation of the tendon using certain techniques.