Bicortical Drilling Research Articles

Easy and safe: A new surgical fixation -technique for acute and chronic anterior instabilities of the sternoclavicular joint: technique and results

Instabilities of the SC joint are a rare injury, accounting for only 3% of all injuries of the shoulder-girdle. While acute posterior dislocations are an emergency and require immediate surgical intervention, anterior instabilities (first and second degree according to Allman) can mostly be treated conservatively. Chronic and highly instable acute anterior instabilities often imposes a significant limitation on the lives of affected patients. Currently, there is no established therapeutic algorithm in place. This retrospective case series with prospective collection of data was performed at a level-I trauma centre. Patients treated surgically for anterior SC joint instabilities between January 2013 and December 2019 and with a minimum follow-up of 24 months were included. The injuries comprised of six acute anterior dislocations treated with tape-cerclage in a "figure-of-8" configuration; twelve patients with chronic anterior SC instabilities were treated with autologous tendon grafts. For one highly unstable chronic anterior instability in addition to the tendon graft synthetic suture material was applied. The clinical evaluation consisted of a physical examination and a standardized questionnaire, which included subjective and objective shoulder scores. Out of 24, 19 patients (79%) with an average age of 32 years ± 15 were available for follow-up. 63% of the patients were male. After a mean follow-up of 57 months, the mean age- and sex-adapted Constant-Murley Shoulder Score (CS) of acute anterior luxations amounted to 90 points ± 20, Nottingham Clavicle Score (NCS) to 81 points ± 22 and DASH Score to 11 points ± 18. Chronic anterior instabilities had a mean CS of 90 points ± 12, NCS of 83 points ± 17 and DASH Score of 4 points ± 5. The study shows a complication rate of 10%. Two patients underwent revision surgery. To conlude, monocortical SCJ fixation in a "figure-of-8" fashion presents a low risk for complication and a low revision rate and can achieve equally good functional outcome after the treatment of highly unstable acute and chronic anterior SCJ instabilities than other published techniques. Our approach presents less risk to the neurovascular structures of the mediastinum than other published techniques requiring bicortical drilling, therefore making the technique more accessible to hospitals without a cardiothoracic surgical background.

K-wire is more damaging than standard or acrylic drill bits when evaluating torsional properties of rabbit (Oryctolagus cuniculi) femurs.

The objective of this study is to compare drilling variables and torsional mechanical properties of rabbit femora after bicortical drilling with a 1.5-mm standard surgical drill bit, acrylic drill bit, and K-wire. 24 pairs of rabbit femora. After drilling under controlled axial displacement rate, each bone was biaxially loaded in compression followed by rapid external torsion to failure. Maximum axial thrust force, maximum drill torque, integral of force and displacement, change in temperature, maximum power spectral density of the torque signal, torque vibration, and torque and angle at the yield and failure points were collected. Pre- and postyield stiffness, yield and failure energies, and postyield energy were calculated. The work required to drill through the cis- and transcortices (integral of force and displacement) was greater for the K-wire, followed by the acrylic and then standard drill bits, respectively. The K-wire demonstrated higher maximum torque than the drill bits at the ciscortex, and the force of drilling was significantly greater. The vibration data was greater with the acrylic and standard drill bits than the K-wire. There was no difference in torsional strength between drilling types. Mechanical differences exist between different drill bits and K-wire and demonstrate that the K-wire is overall more damaging than the surgical drill bit.

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

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. 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. 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%). 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.

Optimizing pectoralis major tendon repair: a modified knotless suture anchor technique using high-strength suture and tape

BackgroundRupture of the pectoralis major tendon is infrequent but has shown an increased incidence in athletes, particularly weightlifters during bench presses. Various techniques for repair exist, yet no established gold standard has been defined. MethodsWe present a modified surgical technique utilizing knotless suture anchors for pectoralis major tendon repair. The technique involves bringing the tendon end superiorly and inferiorly to the decorticated bone surface, ensuring broader tendon-to-bone contact. Knotless anchors with a unique suture locking mechanism facilitate tension adjustment. Additionally, the repair's strength is reinforced by employing both surgical tape and high-strength suture. ResultsThe utilization of both surgical tape and high-strength suture in conjunction with knotless suture anchors provides a secure and stable construct. This approach minimizes the risk of failure, reduces the potential for neurovascular injury associated with bicortical drilling, preserves imaging quality due to the absence of metal artifacts, and helps avoid the risk of fracture associated with traditional methods. However, surgeons should be aware of a potential disadvantage of increased surgical costs compared to traditional techniques. ConclusionsOur modified technique offers multiple advantages, including increased tendon-to-bone contact, enhanced stability, reduced neurovascular risks, and avoidance of potential fractures. This makes it a valuable option for successful pectoralis major tendon repairs. Surgeons should consider its benefits and weigh them against the associated costs for optimal patient care.

Bi-Cortical transhumeral drilling for biceps tenodesis – Is it safe?

BackgroundBiceps tenodesis is an effective procedure performed to treat shoulder pain originating from the long head biceps tendon. In arthroscopic biceps tenodesis unicortical drilling of the humerus is more commonly practiced as it is considered safe to the vital structures lying posterior to the proximal humerus. Many surgeons are wary of the bi-cortical approach as it poses a risk to these vital structures. The aim of this study was to establish whether bi-cortical drilling in proximal humerus is safe or not. Our second purpose was to find a safe zone (if any) for bi-cortical drilling if bi-cortical drilling is safe. MethodsThis study is a descriptive study conducted on cadaveric shoulders. Bilateral shoulders and arms of ten fresh-frozen cadavers (mean age 77.7 y) were dissected. Four landmarks in the dissected humerus were identified. They were superior margin of the bicipital groove, center of the bicipital groove, upper and lower border of pectoralis major insertion. Bi-cortical trans-humeral pinning was done in the humerus at all these points so that the pin exited through the posterior cortex of the humerus. The shortest distance between the pin and the nearest vital structure namely axillary nerve, radial nerve, articular surface of the humeral head, and cephalic vein was calculated from each fixed landmark. ResultsWe established that bi-cortical drilling in proximal humerus was safe. The safe zone established for bi-cortical biceps tenodesis is at the middle of bicipital groove, which is 18.00 ± 4.02 mm inferior to the groove’s upper border. The boundaries of the safe zone lie 9.39 mm superiorly and 9.40 mm inferiorly to the middle of the bicipital groove. ConclusionThe center of the established safe zone for bi-cortical trans-humeral pinning was 18 mm inferior to the bicipital groove’s upper border.

The Proximity of the Axillary Nerve During Keyhole Tenodesis of the Long Head of the Biceps Tendon: A Cadaveric Study.

Over time, surgical management for conditions involving the long head of the biceps tendon (LHBT) has evolved. Some techniques, such as keyhole tenodesis proposes bicortical drilling, however, carries an axillary nerve injury risk. The goal of our cadaveric study was to see if we could keep a safe zone between the point of exit of keyhole tenodesis of biceps and axillary nerve. The study was performed on ten shoulders from five fresh frozen cadavers. Between the lower border of the transverse humeral ligament (THL) and the superior margin of the pectoralis major insertion at the lowest limit of the bicipital groove, a beath pin was driven through with the help of the modified tip aimer tibial jig procured from the anterior cruciate ligament reconstruction (ACL) set, which was fixed at an arc of 45°. The distance between the axillary nerve and beath pin at the exit point was measured. The biceps tendon musculotendinous junction was followed all the way to the inferiorly and biceps tendon was found in the groove. The average distance from the axillary nerve to the exit point of the beath pin was 17.7mm (range 14.4-20.9mm, 95% CI). The axillary nerve is not injured during bicortical drilling when keyhole tenodesis of biceps is performed at the distal limit of the groove of biceps. The area in the biciptal groove between inferior margin of THL and superior border of pectoralis major insertion is safe area for biceps tenodesis.

Tensionable Distal Biceps Tendon Repair With Intramedullary Knotless All-Suture Anchors and FiberLoop w/FiberTag Suture

Distal biceps tendon rupture is commonly repaired via bicortical drilling, extramedullary cortical button placement, and inlay tendon fixation. A retensionable technique with unicortical drilling, intramedullary knotless all-suture anchors placement, and onlay tendon fixation is presented, incorporating up-to-date advances in tendon-bone healing basic science, biceps tendon/radial tuberosity biomechanics, and knotless all-suture implant technology to facilitate radial tuberosity bone preservation, anatomic footprint restoration, improved suture-tendon connection security, and avoidance of drilling and implant-related injury to the posterior interosseous nerve.

Sialocele of Submandibular Gland, an Unreported Complication of Bilateral Sagittal Split Osteotomy

Bilateral sagittal split osteotomy is a routine procedure with predictable and well-known complications. The authors report a thitherto unreported complication of bilateral sagittal split osteotomy presenting as a postoperative sialocele of submandibular salivary gland tissue in the floor of the mouth. The sialocele was probably caused by overinstrumentation and injury to sublingual salivary tissues or Wharton's duct during bicortical drilling or screw fixation. This iatrogenic sialocele was managed conservatively with multiple aspiration and compression dressings. Although rare and unreported so far this complication may be included in the preoperative consent process.

Risk of Posterior Interosseous Nerve Injury During Distal Biceps Tendon Repair Using a Cortical Button

PurposeTo evaluate the possibility of posterior interosseous nerve (PIN) injury during cortical button deployment and seating associated with bicortical drilling and passage of the cortical button across the distal cortex when repairing a distal biceps rupture in a cadaveric model.MethodsEach cadaver was placed in the supine position with the arm extended. A single 4 cm transverse incision was made in the region of the radial tuberosity, 3–4 cm distal to the antecubital fossa flexion crease, and dissected down to the radial tuberosity. A #2 looped nonabsorbable suture was used to baseball stitch the musculotendinous junction to the distal 2.5 cm end of the tendon. A 3.2 mm cannulated drill bit (Arthrex) was used to create a bicortical drill hole in the center of the radial tuberosity aiming 30° ulnar to maximize the distance from the PIN. Fluoroscopy was used to confirm drill placement in the radial tuberosity for all specimens. The posterior aspect of the elbow in all cadavers was subsequently dissected out to directly visualize how far the cannulated drill was from the PIN.ResultsTwelve cadavers, average age 57.4 years (range, 27–83 years), were dissected. During deployment, the cortical button contacted the PIN directly in 6 extremities. The cortical button came within 6 mm of the PIN in eleven extremities. In 8 specimens, the cortical button was within 2 mm of the PIN. The PIN was caught directly under the cortical button in one specimen.ConclusionsPlacement of a biceps cortical button bicortically when repairing a distal biceps tendon may increase the risk of injury to the PIN during cortical button deployment and seating.Type of study/level of evidenceTherapeutic IV.

Anterior Odontoid Screw Fixation for Pediatric and Adolescent Odontoid Fractures: Single-Center Experience Over a Decade

Management of pediatric odontoid fractures is tricky and controversial. This study will enrich world literature with intricacies of anterior odontoid screw (OS) fixation in the pediatric population learned over the last decade. In this retrospective study, all patients with pediatric odontoid fracture who underwent anterior odontoid screw fixation from January 2010 to December 2019 were included and evaluated for surgical outcome. Thirteen patients were included in this study (mean age, 15 years; range, 6-18 years; male/female, 11:2; type II, 10; type IIA, 1; type III, 2). Common causes of injury were motor vehicle accidents (61.5%) followed by fall from height (38.5%) and all were acute fractures (2-30 days). Five patients had neurologic deficits. Accurate placement of screw was achieved in 92.3% of patients, including all 9 patients who used intraoperative O-arm. K wire migration during bicortical drilling resulted in neurovascular injury, with 1 mortality (7.7%). The remaining 12 patients were available for follow-up (mean, 36 months; range, 20-72 months) and all had preservation of neck movements. Successful OS fixation was achieved in 84.6% of patients, including 1 patient (7.7%) who had a fibrous union. One patient (8.3%) had nonunion because of migration of the screw head in the C2 body. Anterior odontoid screw fixation in the pediatric population provides good functional outcomes with instant fixation by direct osteosynthesis. However, the surgeon should be meticulous in the surgical approach and should achieve a lag effect. The surgeon should stop after engaging the outer cortex of the odontoid peg with K wire to avoid cranial migration. Intraoperative O-arm guidance is useful.

Arthroscopic Biceps Tenodesis by Bicortical Drilling Technique

Pain arising from the long head of biceps tendon can cause significant disability of the shoulder. In young and physically demanding patients, biceps tenodesis is advised, in which the biceps tendon is cut from the native origin and fixed distally. Many methods have been proposed for this. This Technical Note describes arthroscopic biceps tenodesis in the bicipital groove by a bicortical drilling technique. The far cortex is breached only once by a guide wire, and the reamers do not breach the far cortex. The tendon is fixed in the new position using a PopLok anchor. This technique is safe and easy to perform but presents a learning curve.

Do Resident Surgical Volumes and Level of Training Correlate with Improved Performance on Psychomotor Skills Tasks: Construct Validity Testing of an ASSH Training Platform (STEP)?

Background:The Surgical Training and Educational Platform (STEP) was developed by the American Society for Surgery of the Hand (ASSH) as a cost-effective set of surgical simulation modules designed to assess critical skills in hand surgery. Previous study demonstrated that STEP can differentiate between novice trainees and board-certified, certificate of added qualification hand surgeons. The purpose of this study was to assess construct validity of STEP by testing its ability to differentiate psychomotor skill level among intermediate trainees.Methods:We evaluated 30 residents from 2 orthopaedic residency programs on 8 modules: (1) lag screw fixation, (2) depth of plunge during bicortical drilling, (3) flexor tendon repair, (4) phalangeal fracture pinning, (5) central axis scaphoid fixation, (6) full-thickness skin graft harvest, (7) microsurgery, and (8) wrist arthroscopy. Spearman correlation was used to correlate total and task-specific scores to case log numbers, months in training, and number of hand surgery rotations.Results:Senior residents had significantly higher mean number of total cases in their total case log (mean difference 96.2, 95% confidence interval [CI] 67.5-124.8, p < 0.01) and number of task-specific cases. Moderate correlation was observed between case log numbers and scaphoid fixation score (rs = 0.423, 95% CI 0.07-0.69) and total score (rs = 0.584, 95% CI 0.25-0.79). Moderate correlation was observed between months in training with: scaphoid fixation (rs = 0.377, 95% CI 0.01-0.66) and microsurgery (rs = 0.483, 95% CI 0.13-0.73); strong correlation was seen with total score (rs = 0.656, 95% CI 0.35-0.83). Moderate correlation with number of hand surgery rotations was observed with tendon repair (rs = 0.362, 95% CI −0.01 to 0.65), skin graft (rs = 0.385, 95% CI 0.01-0.66), wrist arthroscopy (rs = 0.391, 95% CI 0.02-0.67), microsurgery (rs = 0.461, 95% CI 0.10-0.71), and scaphoid fixation (rs = 0.578, 95% CI 0.25-0.79); and strong correlation was seen with total score (rs = 0.670, 95% CI 0.37-0.84).Discussion/Conclusion:The STEP is a validated ASSH education tool that provides a cost-effective simulation for the assessment of fundamental psychomotor skills in hand surgery. Total STEP score correlated with total task-related case volumes as well as months in training and number of hand rotations. Scoring could be modified to improve the fidelity of assessing surgical performance. And, while both time and human resource consuming to perform, administer, and score, this study demonstrates construct validity of STEP in assessing the progression of surgical skill through residency.

Plunging Dangerously: A Quantitative Assessment of Drilling the Clavicle.

Bicortical drilling of the clavicle is associated with risk of iatrogenic damage from plunging given the close proximity of neurovascular structures. This study determined plunge depth during superior-to-inferior clavicle drilling using a standard drill vs drill-sensing technology. Two orthopedic surgeons drilled 10 holes in a fresh cadaveric clavicle with drill-sensing technology in freehand mode (functions as standard orthopedic drill) and another 10 holes with drill-sensing technology in bicortical mode (drill motor stops when the second cortex is breached and depth is measured in real time). The drill-measured depths were compared with computed tomography-measured depths. Distances to the neurovascular structures were also measured. The surgeons' plunge depths were compared using an independent t test. With freehand (standard) drilling, the mean plunge depth was 8.8 mm. For surgeon 1, the range was 5.6 to 15.8 mm (mean, 10.9 mm). For surgeon 2, the range was 3.3 to 11.0 mm (mean, 6.4 mm). The surgeons' plunge depths were significantly different. In bicortical mode, the drill motor stopped when the second cortex was penetrated. Drill-measured depths were verified by computed tomography scan, with a mean difference of 0.8 mm. Mean distances from the clavicle to the neurovascular structures were 15.5 mm for the subclavian vein, 18.0 mm for the subclavian artery, and 8.0 mm for the brachial plexus. Plunge depths differed between surgeons. However, both surgeons' plunge depths were greater than distances to the neurovascular structures, indicating a risk of injury due to plunging. Although a nonspinning drill bit may still cause soft tissue damage, drill-sensing technology may decrease the risk of penetrating soft tissue structures due to plunging. [Orthopedics. 2021;44(1):e36-e42.].

Establishing Validity of a Comprehensive Hand Surgical Training and Educational Platform (STEP)

The purpose of this study was to develop and perform the initial validation for the Surgical Training and Educational Platform (STEP), a cost-effective psychomotor training and assessment instrument designed to teach and evaluate fundamental skills considered critical to competency in hand surgery. An American Society for Surgery of the Hand (ASSH) taskforce of 13 board-certified hand surgeons developed 8 skills considered fundamental to competency in hand surgery including: (1) lag screw fixation of an oblique fracture, (2) depth of plunge during bicortical drilling, (3) central axis scaphoid fixation, (4) phalangeal fracture pinning, (5) flexor tendon repair, (6) microsurgical suturing, (7) full-thickness skin graft harvest, and (8) wrist arthroscopy. The tasks were developed from commercially available, nonclinical supplies at low cost. The startup cost for the entire system was less than $600 USD, with a cost-per-trainee-assessment of approximately $25 USD. After the tasks were finalized, 2 examiners traveled to 8 sites around the country to evaluate 93 surgeons, including 57 board-certified hand surgeons and 36 first-year orthopedic and plastic surgical residents. Scoring criteria for each task were based on a combination of time and clinically relevant quality metrics. Board-certified hand surgeons significantly outperformed surgical trainees on all 8 tasks, demonstrating that the STEP appropriately differentiates the skill level of expert and novice hand surgeons. The STEP is an effective simulator that encompasses a wide range of fundamental psychomotor skills considered critical to competency in hand surgery. Although the STEP tasks are a valuable surgical training tool, further work is required to evaluate and refine the scoring system prior to using it as a critical evaluation of performance. The STEP simulator is a valuable, validated instrument for resident and fellow education and evaluation in hand surgery outside of the operating room.

Suprapectoral biceps tenodesis with bicortical drilling procedures: anatomic analysis of chondral and axillary nerve risk with transhumeral pin guide

Many biceps tenodesis (BT) procedures are described for treating proximal biceps pathology. Axillary nerve injury has been reported during BT using bicortical drilling techniques with variable results depending on the location. In addition, there is a risk of potential articular damage during suprapectoral BT. We sought to determine the distance between the axillary nerve and the posterior passage of a bicortical pin, as well as the risk of articular damage, and to analyze whether a lateral inclination of the pin could avoid the chondral risk during suprapectoral BT with bicortical drilling. Ten cadaveric shoulders were divided into 2 groups. In the first group, we determined the axillary nerve distance from the posterior exit point of 3 pins in a suprapectoral position 15 mm distal to the humeral cartilage: perpendicular, 10° caudal, and 20° caudal inclination. We measured 2 distances from the pin: to the axillary nerve and to the cartilage border. In the second group, we set one pin at the same perpendicular position and set the second pin 15° laterally tilted to determine its extra-articular passage. No pin injured the nerve, whereas all pins showed a transchondral direction. The 20° caudal inclination was the nearest to the nerve (18.8 mm [95% confidence interval, 5.5-32 mm]), but the perpendicular position was the safer position (38.8 mm [95% confidence interval, 28-49.6 mm]). Tilting the pin direction 15° laterally prevented cartilage damage (P = .008). Suprapectoral BT with bicortical drilling performed 15 mm distal to the humeral cartilage is a safe procedure regarding the axillary nerve. A potential humeral chondral injury could be prevented with 15° of lateral inclination of the pin guide.

A Novel Approach for Assessing and Training the Drilling Skills of Orthopaedic Surgeons

Although experiences in the operating room can help surgeons to learn simple bone-drilling techniques, outside training may be better suited for complex procedures. We adapted a rotary handpiece to evaluate the bone-drilling skills of orthopaedic resident physicians during the 2017 Southwest Orthopaedic Trauma Association (SWOTA) motor skills course. Twenty-five postgraduate year (PGY)-1 orthopaedic residents from 7 institutions were asked to perform a bicortical drilling task 3 times both before and after attending a motor skills course. Kinetic and kinematic data were collected using force, acceleration, and visual sensors. Sixteen parameters were measured. The interdependence of these parameters (taken separately for precourse and postcourse performance) is presented. Evidence for motor skill acquisition across a short time scale is elucidated. Noteworthy correlations include overpenetration with force (0.65 mm), palmar-dorsal (P-D) toggle (0.65°), vibration in the P-D direction (0.53 m/s), time (-0.41 sec), and RPM (revolutions per minute; -0.36); time with both RPM (0.38) and P-D toggle (-0.40°); and force with both RPM (-0.41) and P-D toggle (0.32°). Differences in performance before and after the motor skills course include reduction in overpenetration (28.8 to 18.2 mm), reduction in skiving (22% to 6%), and reduction in preparation time (27.3 to 9.65 sec). Additionally, there were several differences in performance by institution that were significant (overpenetration, toggle in the P-D and radial-ulnar [R-U] directions, and both drilling force and drilling time). Understanding how performance and outcome parameters are correlated provides powerful insight into how surgical procedures can be best performed. In particular, we hope that these findings will inform new training paradigms. Variations in resident training from 1 institution to another are evidenced in surgical performance. Similarly, the methods used here to quantify changes in performance across the 3-day SWOTA training course allow a unique vehicle for optimization of these types of training opportunities outside of the operating room.

Deep peroneal nerve has a potential risk of injury during open-wedge high tibial osteotomy.

To assess the risk of injury to the neurovascular bundle on the interosseous membrane of the leg during drilling for distal screw insertion in open-wedge high tibial osteotomy (OWHTO), and to investigate the possible influence of the method of plate placement on the risk. This retrospective study involved, 55 patients (32 with a TomoFix plate, 23 with a TriS plate) who underwent postoperative CT scanning of the knee following OWHTO between 2009 and 2018. The angle and position of the locking plate, and the direction of screw insertion relative to the interosseous membrane were analysed. All distal screws had a risk of neurovascular injury. In particular, 25 screws at the #4 hole (45%) had an extended insertion trajectory that intersected with the interosseous membrane. The angle of the proximal part of the TomoFix plate was a significant risk factor. In contrast, methods of TriS plate placement showed no statistically significant differences. Extended insertion trajectories of distal screws were likely to intersect with the interosseous membrane with the neurovascular bundle potentially on its surface; thus, drilling for bicortical fixation posed a risk of neurovascular injury. The risk increased as the TomoFix plate was placed more medially, suggesting that bicortical drilling must be performed with the utmost attention when the plate is placed at the medial position. Given the particularly high risk at the #3 and #4 screw holes, monocortical fixation of a few distal screws is recommended as long as good stability is ensured.

How to Avoid Posterior Interosseous Nerve Injury During Single-Incision Distal Biceps Repair Drilling.

The posterior interosseous nerve (PIN) is occasionally damaged during distal biceps tendon repair. But to our knowledge, no studies have examined the position of the PIN in relation to the bicipital tuberosity in full supination, which is the recommended position during single-incision distal biceps repair or reconstruction QUESTIONS/PURPOSES: (1) What is the anterior safe zone when exposing the anterior tuberosity with the arm in supination? (2) When drilling the radial tuberosity for bicortical button placement in full supination, how should the drill be angled to avoid PIN injury? Fifteen adult cadaver elbows had the PIN dissected around the proximal radius. The position of the PIN was measured relative to the most ulnar aspect of the radius at three sites in full supination: at the bicipital tuberosity (bicipital tuberosity-PIN), 10 mm proximal to the bicipital tuberosity (bicipital tuberosity-proximal), and 10 mm distal to the bicipital tuberosity (bicipital tuberosity-distal). We made another measurement by drawing a line from the lateral humeral epicondyle to the radial styloid. The point where the PIN intersects this line, when viewed laterally and measured from the lateral humeral epicondyle, was marked and measured to indicate where it wraps around the radius laterally (PIN-lateral). The last measurement (bicipital tuberosity-lateral) was made where the line from the lateral humeral epicondyle to the radial styloid intersected the position of the bicipital tuberosity. This was determined by the point where a perpendicular line from the bicipital tuberosity was drawn laterally to meet with the lateral line. We did this to establish if the PIN adopts its most lateral position on the radius at the same level as the bicipital tuberosity. The anterior safe zone in the approach to the biceps tuberosity extends approximately 15 mm from its prominence (mean, 20.7 mm; range, 16.0-24.1 mm). The PIN crosses the lateral midline from anterior to posterior at 46.0 mm (range, 31.2-67.0 mm) from the lateral epicondyle (lying directly opposite the bicipital tuberosity at nearly the same level); therefore, the drill exit should be posterior to lateral midline while aiming proximally to the bicipital tuberosity. Our anterior safe zone found that the PIN travels from an anterior position on the radius, when measuring 1 cm proximal to the bicipital tuberosity to a lateral position on the radius at the level of the bicipital tuberosity prominence (on the contralateral cortex), to a slightly more posterior position on the radius 1 cm distal to the bicipital tuberosity. Typically, the PIN sits directly opposite the biceps tuberosity, often directly on the cortex of the radius when the forearm is in full supination. Because of these findings, perpendicular bicortical drilling starting at the bicipital tuberosity should be avoided. A more proximal and ulnar drilling angle is recommended. Defining a safe zone for an anterior approach seems to be clinically unhelpful due to the high anatomical variability that exists for the position of the PIN around the proximal radius. Future studies could attempt to confirm our findings with the analysis of noncadaveric imaging in three different planes using such modalities as MRI to avoid the effects of tissue distortion during cadaveric preparation and dissection.

Anatomic Single-Incision Repair of Distal Biceps Tendon Ruptures Using Intramedullary Soft Anchors

Distal biceps tendon ruptures are uncommon injuries responsible for only 3% of all injuries to the biceps tendon. For most of these cases, unless the patient is elderly or infirm, conservative management should be avoided and the injury should be treated with a surgical procedure to reattach the bicep tendon to the radial tuberosity. In this Technical Note and accompanying video, we describe an anatomic single-incision technique using 2 intramedullary soft anchors, which decreases the likelihood of complications associated with bicortical drilling and metal suspensory fixation.

Posterior Interosseous Nerve Proximity to Cortical Button Implant for Distal Biceps Repair With Single and 2-Incision Approaches

Fixation with a cortical button is the biomechanically strongest surgical approach for distal biceps repair, and utilization of the 2-incision approach may provide a more anatomical repair and improved terminal supination strength. The risk of injury to the posterior interosseous nerve (PIN) associated with this approach requires further investigation. A distal biceps repair with a cortical button was performed on 10 cadavers, 5 utilizing the single-incision approach and 5 utilizing the 2-incision approach. Contrast was injected into the radial nerve and computed tomography scans were obtained. The distance between the drilled cortical perforation and the PIN was measured. The mean distance from the cortical perforation to the PIN was not significantly different between approaches (9.4 mm and 8.8 mm). A PIN entrapment was seen in 0 out of 5 for the single-incision approach and 1 out of 5 for the 2-incision approach. Distal biceps repair with cortical button fixation places the PIN at risk of injury regardless of the approach used. Methods of fixation that require bicortical drilling should be especially avoided when using the 2-incision approach. Distal biceps repair utilizing bicortical drilling for fixation through a 2-incision approach poses high risk of injury to the PIN and should be avoided.