Distal biceps tendon ruptures occur with the almost extended elbow and supinated forearm - an online video analytic study

PoCUS identification of distal biceps tendon rupture: a case report

BACKGROUND

In the Emergency Department (ED), patients may present with various injuries that damage muscles, tendons, ligaments, and bony structures. Fractures, joint dislocations, strains, and sprains are prevalent among them. However, distal biceps tendon ruptures are uncommon.

CASE REPORT

Here, we report a case of a young man presented to the ED with a complaint of left arm pain following a martial arts activity. The diagnosis of distal biceps tendon rupture was made using a point-of-care ultrasound (PoCUS), and an early referral to the orthopedic service was provided.

CONCLUSION

This case highlights the utility of point-of-care ultrasound in assessing musculoskeletal injuries in the ED. Early incorporation of PoCUS into routine clinical practice can potentially improve the overall care of musculoskeletal injuries.

[Can a fall onto the shoulder (direct impact) cause a rotator cuff tear?]

The question of whether a fall directly onto the shoulder can cause a rotator cuff tear has occupied doctors (and courts) for many years. Experts who rely on the medical insurance literature usually reject the causality of the incident. There are no scientific studies on this. The report below describes a typical case in which a fall directly onto the shoulder caused a massive rotator cuff tear.

Prevalence and clinical implications of heterotopic ossification after distal biceps tendon repair

Complete distal biceps tendon ruptures are relatively uncommon. Conservative treatment may result in persistent pain and weakness. Therefore, surgical repair is usually indicated in order to restore strength. Different surgical techniques and fixation methods have been described. The most reported complications after surgery are iatrogenic nerve damage, heterotopic ossification (HO) and re-rupture. Heterotopic ossification can be variable in size. Significant HO can limit range of motion while minor HO often remains asymptomatic. The overall presence of HO is likely underreported in literature, as imaging is reserved for symptomatic patients. The purpose of this study is to report the prevalence and clinical implications of heterotopic ossification after surgical repair of the distal biceps tendon. This retrospective study assessed the prevalence and clinical relevance of postoperative HO after distal biceps tendon repair. CT-scans were used to evaluate size and location of the HO. VAS scores, DASH scores, MEPI, and range of motion (ROM) were assessed to evaluate pain, patient satisfaction and elbow function. HO was observed on CT images of 19 out of 35 patients (54%). The use of interference screws, timing of surgery after rupture and timing of radiographic assessment postoperatively did not influence the prevalence of HO. The presence of HO had no statistically significant impact on the VAS scores, ROM measurements and MEPI and DASH scores. According to our findings, the overall incidence of HO is higher than previously reported but there are no differences in clinical outcomes when compared to patients without HO.

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.

Distale Bizepssehnenruptur

Die Ruptur der distalen Bizepssehne tritt am häufigsten bei Männern im mittleren Alter auf (30 bis 50 Jahre). Der typische Mechanismus ist die exzentrische Belastung in strecknaher Ellbogenstellung in Supination, wobei diese Verletzung mit Kraftsport und körperlich belastender Tätigkeit assoziiert ist. Epidemiologische Daten weisen auf eine Zunahme von distalen Bizepsrupturen in den letzten Jahrzehnten hin. Risikofaktoren wie die Verwendung anaboler Steroide, Kraftsport und Nikotinabusus zeigen einen Zusammenhang mit der Verletzung. Bei reduziertem Patientenanspruch oder relevanten Komorbiditäten ist auch unter einer konservativen Behandlung ein gutes funktionelles Ergebnis mit subjektiv guter Patientenzufriedenheit zu erreichen, allerdings unter zu erwartender relevanter Kraftminderung in Flexion (20 %) und Supination (40 %). Durch eine operative Refixation lässt sich das beste funktionelle Resultat erzielen, allerdings einhergehend mit einem nicht unerheblichen Komplikationsrisiko.

Challenging the mechanism of distal biceps tendon rupture using a video analysis study

AIMS

The conventionally described mechanism of distal biceps tendon rupture (DBTR) is of a 'considerable extension force suddenly applied to a resisting, actively flexed forearm'. This has been commonly paraphrased as an 'eccentric contracture to a flexed elbow'. Both definitions have been frequently used in the literature with little objective analysis or citation. The aim of the present study was to use video footage of real time distal biceps ruptures to revisit and objectively define the mechanism of injury.

METHODS

An online search identified 61 videos reporting a DBTR. Videos were independently reviewed by three surgeons to assess forearm rotation, elbow flexion, shoulder position, and type of muscle contraction being exerted at the time of rupture. Prospective data on mechanism of injury and arm position was also collected concurrently for 22 consecutive patients diagnosed with an acute DBTR in order to corroborate the video analysis.

RESULTS

Four videos were excluded, leaving 57 for final analysis. Mechanisms of injury included deadlift, bicep curls, calisthenics, arm wrestling, heavy lifting, and boxing. In all, 98% of ruptures occurred with the arm in supination and 89% occurred at 0° to 10° of elbow flexion. Regarding muscle activity, 88% occurred during isometric contraction, 7% during eccentric contraction, and 5% during concentric contraction. Interobserver correlation scores were calculated as 0.66 to 0.89 using the free-marginal Fleiss Kappa tool. The prospectively collected patient data was consistent with the video analysis, with 82% of injuries occurring in supination and 95% in relative elbow extension.

CONCLUSION

Contrary to the classically described injury mechanism, in this study the usual arm position during DBTR was forearm supination and elbow extension, and the muscle contraction was typically isometric. This was demonstrated for both video analysis and 'real' patients across a range of activities leading to rupture.Cite this article: Bone Jt Open 2022;3(10):826-831.