Enthesopathy of the Bicipital Tuberosity of the Radius Treated Under Intraoperative Computed Tomography

There is no report of the application of intraoperative computed tomography to the extremities, and its usefulness is not mentioned. We present a case of a patient with the elbow pain and loss of the forearm rotation due to the prominent bicipital tuberosity of the radius, which was diagnosed as enthesopathy. Surgical treatment to excise the prominent part of the bicipital tuberosity of the radius was recommended. However, it is difficult to perform the appropriate excision of the abnormal prominent part because of complications such as bicipital tendon rupture. The patient was successfully treated by surgical resection under the control of intraoperative computed tomography. Intraoperative computed tomography scan is a useful tool to assess the remaining volume of the abnormal bones.

Distance of the Posterior Interosseous Nerve From the Bicipital (Radial) Tuberosity at Varying Positions of Forearm Rotation: A Magnetic Resonance Imaging Study With Clinical Implications

Background: The proximity of the posterior interosseous nerve (PIN) to the bicipital tuberosity is clinically important in the increasingly popular anterior single-incision technique for distal biceps tendon repair. Maximal forearm supination is recommended during tendon reinsertion from the anterior approach to ensure the maximum protective distance of the PIN from the bicipital tuberosity. Purpose: To compare the location of the PIN on magnetic resonance imaging (MRI) relative to bicortical drill pin instrumentation for suspensory button fixation via the anterior single-incision approach in varying positions of forearm rotation. Study Design: Descriptive laboratory study. Methods: Axial, non–fat suppressed, T1-weighted MRI scans of the elbow were obtained in positions of maximal supination, neutral, and maximal pronation in 13 skeletally mature individuals. Distances were measured from the PIN to (1) the simulated path of an entering guidewire (GWE-PIN) and (2) the cortical starting point of the guidewire on the bicipital tuberosity (CSP-PIN) achievable from the single-incision approach. To radiographically define the location of the nerve relative to constant landmarks, measurements were also made from the PIN to (3) the prominent-most point on the bicipital tuberosity (BTP-PIN) and (4) a perpendicular plane trajectory from the bicipital tuberosity exiting the opposing radial cortex (PPT-PIN). All measurements were subsequently compared between positions of pronation, neutral, and supination. In supination only, BTP-PIN and PPT-PIN measurements were made and compared at 3 sequential axial levels to evaluate the longitudinal course of the nerve relative to the bicipital tuberosity. Results: Of the 13 study participants, mean age was 38.77 years, and mean body mass index was 25.58. Five participants were female, and 5 left and 8 right elbow MRI scans were reviewed. The GWE-PIN was significantly greater in supination (mean ± SD, 16.01 ± 2.9 mm) compared with pronation (13.66 ± 2.5 mm) ( P < .005). The mean CSP-PIN was significantly greater in supination (16.20 ± 2.8 mm) compared with pronation (14.18 ± 2.4 mm) ( P < .013).The mean PPT-PIN was significantly greater in supination (9.00 ± 3.0 mm) compared with both pronation (1.96 ± 1.2 mm; P < .001) and neutral (4.73 ± 2.6 mm; P < .001). The mean BTP-PIN was 20.54 ± 3.0, 20.81 ± 2.7, and 20.35 ± 2.9 mm in pronation, neutral, and supination, respectively, which did not significantly differ between positions. In supination, the proximal, midportion, and distal measurements of BTP-PIN did not significantly differ. The proximal PPT-PIN distance (9.08 ± 2.9 mm) was significantly greater than midportion PPT-PIN (5.85 ± 2.4 mm; P < .001) and distal BTP-PIN (2.27 ± 1.8 mm; P < .001). Conclusion: This MRI study supports existing evidence that supination protects the PIN from the entering guidewire instrumentation during anterior, single-incision biceps tendon repair using cortical button fixation. The distances between the entering guidewire trajectory and PIN show that guidewire-inflicted injury to the nerve is unlikely during the anterior single-incision approach. Clinical Relevance: When a safe technique is used, PIN injuries during anterior repair are likely the result of aberrant retractor placement, and we recommend against the use of retractors deep to the radial neck. Guidewire placement as close as possible to the anatomic footprint of the biceps tendon is safe from the anterior approach. MRI evaluation confirms that ulnar and proximal guidewire trajectory is the safest technique when using single-incision bicortical suspensory button fixation.

Minimal Damage to the Supinator Muscle After the Double-Incision Technique for Distal Biceps Tendon Repair

Background: The effect of the double-incision technique on the supinator muscle is unclear. Purpose: The aim of this study was to quantify fatty atrophy of the supinator muscle and map the area of muscle damage. Study Design: Case series; Level of evidence, 4. Methods: A total of 19 male patients (median age, 43 years) who underwent distal biceps tendon repair were included in the analysis. Patients with a minimum of 12 months of follow-up were included. The following variables were analyzed: range of motion; shortened version of Disabilities of the Arm, Shoulder and Hand (QuickDASH) score; Summary Outcome Determination (SOD) score; and isokinetic peak force and endurance in supination. Quantitative analysis and mapping of fatty infiltration of the supinator muscle were based on the calculation of proton density fat fraction on magnetic resonance imaging scans of both elbows using the IDEAL (Iterative Decomposition of Echoes of Asymmetrical Length) sequence. Results: At an average follow-up of 24 months (range, 12-64 months), the median SOD score was 9.0 (95% CI, 7.8-9.4), and the mean QuickDASH score was 6.7 (95% CI, 0.0-14.1). A difference of 17% in peak torque was measured between repaired and nonrepaired elbows (repaired elbow: 9.7 N·m; nonrepaired elbow: 11.7 N·m; P = .11). Endurance was better in the repaired elbow than the nonrepaired elbow (8.4% vs 14.9% work fatigue, respectively; P = .02). The average fat fraction of the supinator muscle was 19% (95% CI, 16%-21%) in repaired elbows and 14% (95% CI, 13%-16%) in contralateral elbows ( P = .04). The increase in fat fraction was located in a limited area between the radius and ulna at the level of the bicipital tuberosity. Conclusion: The assessment of the supinator muscle showed a limited increase in fat fraction between the radius and ulna at the level of the bicipital tuberosity. No significant effect on supination strength was highlighted.

Bilateral Solitary Osteochondroma of the Bicipital Tuberosity Accompanied with Painful Clicking: A Case Report and Literature Review

Although osteochondroma is a benign bone tumor often observed in daily practice, solitary osteochondroma of the bicipital tuberosity is rarely observed. Herein, we report a case of bilateral solitary osteochondroma of the bicipital tuberosity. A 76-year-old woman experienced crackling and painful clicking bilaterally in her proximal forearms during pronation-supination. X-ray imaging, computed tomography, and magnetic resonance imaging revealed that the symptom was caused by bilateral solitary osteochondroma of the bicipital tuberosity. Bone tumor resection was performed on both sides. After surgery, the symptoms improved. X-ray imaging performed 2 years after surgery revealed no tumor recurrence. When painful clicking occurs around the elbow joint, a solitary osteochondroma of the bicipital tuberosity should be suspected; this symptom should be examined, and the surgeon should consider surgery positively. Exposed subchondral bone may rub against, collide with, or impinge upon the ulna during forearm pronation-supination and induce pain.

Biomechanics of the Proximal Radius Following Drilling of the Bicipital Tuberosity to Mimic Cortical Button Distal Biceps Repair Technique

Background: A fracture through the proximal radius is a theoretical concern after cortical button distal biceps fixation in an active patient. The permanent, nonossified cortical defect and medullary tunnel is at risk during a fall eliciting rotational and compressive forces. We hypothesized that during simulated torsion and compression, in comparison with unaltered specimens, the cortical button distal biceps repair model would have decreased torsional and compressive strength and would fracture in the vicinity of the bicipital tuberosity bone tunnel. Methods: Sixteen fourth-generation composite radius Sawbones models were used in this controlled laboratory study. A bone tunnel was created through the bicipital tuberosity to mimic the exact bone tunnel, 8 mm near cortex and 3.2 mm far cortex, made for the BicepsButton distal biceps tendon repair. The radius was then prepared and mounted on either a torsional or compression testing device and compared with undrilled control specimens. Results: Compression tests resulted in average failure loads of 9015.2 N in controls versus 8253.25 N in drilled specimens ( P = .074). Torsional testing resulted in an average failure torque of 27.3 Nm in controls and 19.3 Nm in drilled specimens ( P = .024). Average fracture angle was 35.1° in controls versus 21.1° in drilled. Gross fracture patterns were similar in compression testing; however, in torsional testing all fractures occurred through the bone tunnel in the drilled group. Conclusion: There are weaknesses in the vicinity of the bone tunnel in the proximal radius during biomechanical stress testing which may not be clinically relevant in nature. Clinical Relevance: In cortical button fixation, distal biceps repairs creates a permanent, nonossified cortical defect with tendon interposed in the bone tunnel, which can alter the biomechanical properties of the proximal radius during compressive and torsional loading.

BICIPITAL TUBEROSITY OSTEOCHONDROMA CAUSING PAINFUL CLICKING AROUND THE WRIST: CASE REPORT AND LITERATURE REVIEW

Osteochondromatas of bicipital tuberosity are rare, most commonly occurring as metaphyseal benign tumours of the long bones. The usual presenting symptoms are pain and reduced rotation of the elbow. A painful clunk in the wrist as a presenting symptom has not been described before. We present a young lady with a two-year history of a painful clunk in her wrist. Her case presented a diagnostic challenge, as the pain and the click originated from her elbow and radiated down her forearm to the wrist. She underwent several radiological studies, and examination under anaesthesia confirmed the diagnosis. Excision was performed resulting in complete resolution of her symptoms. Along with painful clunk in the wrist originating from the elbow, an enlarged radial tuberosity should raise a high index of suspicion, and MRI scans and examination under image intensification can aid in the diagnosis of radial tuberosity osteochondroma.