Proximal Tibia Fracture Through Suture Augmentation Sites Following ACL/MCL Repairs: A Case Report.

CASE: A 35-year-old man sustained a proximal tibia fracture from a low-energy mechanism 1 year after anterior cruciate and medial collateral ligament repairs with suture augmentation (SA). The fracture propagated through both tibial SA anchor sites. Following intramedullary tibial nailing, he returned to his prior level of function. CONCLUSION: While complications of SA for ligamentous procedures are rare, these techniques are being implemented more frequently and the full complication profile is yet to be determined. Our report documents a new complication and potential risk factors that surgeons should consider when performing SA for multiligament knee surgery in active individuals.

Biomechanical Comparison of Anterior Cervical Plate Fixation Versus Integrated Fixation Cage for Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: Cadaveric, biomechanic study. OBJECTIVE: To compare the range of motion profiles of the cervical spine following one-level anterior cervical discectomy and fusion (ACDF) constructs instrumented with either an interbody cage and anterior plate or integrated fixation cage in a cadaveric model. SUMMARY OF BACKGROUND DATA: While anterior plates with interbody cages are the most common construct of fixation in ACDF, newer integrated cage-plate devices seek to provide similar stability with a decreased implant profile. However, differences in postoperative cervical range of motion between the 2 constructs remain unclear. METHODS: Six cadaveric spines were segmented into 2 functional spine units (FSUs): C2-C5 and C6-T2. Each FSU was nondestructively bent in flexion-extension (FE), right-left lateral bending (LB), and right-left axial rotation (AR) at a rate of 0.5°/s under a constant axial load until a limit of 2-Nm was reached to evaluate baseline range of motion (ROM). Matched pairs were then randomly assigned to undergo instrumentation with either the standard anterior cage and plate (CP) or the integrated fixation cage (IF). Following instrumentation, ROM was then remeasured as previously described. RESULTS: For CP fixation, ROM increased by 61.2±31.7% for FE, 36.3±20.4% for LB, and 31.7±19.1% for AR. For IF fixation, ROM increased by 64.2±15.5% for FE, 56.7±39.8% for LB, and 94.5±65.1% for AR. There was no significant difference in motion between each group across FE, LB, and AR. CONCLUSION: This biomechanical study demonstrated increased motion in both the CP and IF groups relative to the intact, un-instrumented state. However, our model showed no differences in ROM between CP and IF constructs in any direction of motion. These results suggest that either method of instrumentation is a suitable option for ACDF with respect to constructing stiffness at time zero.

Hounsfield Unit-Calculated Bone Mineral Density Loss Following Combat-Related Lower Extremity Amputations.

BACKGROUND: After combat-related lower extremity amputations, patients rapidly lose bone mineral density (BMD). As serial dual x-ray absorptiometry (DXA) scans are rarely performed in this setting, it is difficult to determine the timeline for bone loss and recovery or the role of interventions. However, a strong correlation has been demonstrated between DXA BMD and computed tomography (CT) signal attenuation. We sought to leverage multiple CT scans obtained after trauma to develop a predictive model for BMD after combat-related lower extremity amputations. METHODS: We reviewed amputations performed within the United States military between 2003 and 2016 in patients with multiple CT scans. We collected pertinent clinical information, including amputation level(s), complications, and time to weight-bearing. The primary outcome measure was the development of low BMD, estimated in Hounsfield units (HU) from CT scans with use of a previously validated method. One hundred and twenty-eight patients with 613 femoral neck CT scans were available for analysis. A least absolute shrinkage and selection operator (LASSO) multiple logistic regression analysis was applied to determine the effects of modifiable and non-modifiable variables on BMD. A random-effects model was applied to determine which factors were most predictive of low BMD and to quantify their effects. RESULTS: Both amputated and non-amputated extremities demonstrated substantial BMD loss, which stabilized approximately 3 years after the injury. Loss of BMD followed a logarithmic pattern, stabilizing after 1,000 days. On average, amputated limbs lost approximately 100 HU of BMD after 1,000 days. Other factors identified by the mixed-effects model included nonambulatory status (-33.5 HU), age at injury (-3.4 HU per year), surgical complications delaying weight-bearing (-21.3 HU), transtibial amputation (20.9 HU), and active vitamin-D treatment (-19.7 HU). CONCLUSIONS: Patients with combat-related lower extremity amputations experience an initially rapid decline in BMD in both intact and amputated limbs as a result of both modifiable and non-modifiable influences, including time to walking, amputation level, surgical complications, and age. The paradoxical association of vitamin-D supplementation with lower HU likely reflects this treatment being assigned to patients with low BMD. This model may assist with clinical decision-making prior to performing lower extremity amputation and also may assist providers with postoperative decision-making to optimize management for prophylaxis against osteoporosis. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Subcortical Backup Tibial Fixation in Anterior Cruciate Ligament Reconstruction Has Similar Maximal Strength to Current Techniques.

Purpose: To evaluate the biomechanical profile of subcortical backup fixation (subcortical button [SB]) in anterior cruciate ligament (ACL) reconstruction as compared with a bicortical post and washer (BP) and suture anchor (SA) when used with interference screw (IS) primary fixation and to evaluate the utility of backup fixation for tibial fixation with extramedullary cortical button primary fixation. Methods: Fifty composite tibias with polyester webbing-simulated graft were used to test constructs across 10 methods. Specimens were separated into the following groups (n = 5): 9-mm IS only, BP (with and without graft and IS), SB (with and without graft and IS), SA (with and without graft and IS), extramedullary suture button (with and without graft and IS), and extramedullary suture button with BP as backup fixation. Specimens were tested under cyclic loading and then loaded to failure. Maximal load at failure, displacement, and stiffness were compared. Results: Without a graft, the SB and BP had similar maximal loads (802.46 ± 185.18 N vs 785.67 ± 100.96 N, P = .560), and both were stronger than the SA (368.13 ± 77.26 N, P < .001). With graft and an IS, there was no significant difference in maximal load between the BP (1,461.27 ± 173.75 N), SB (1,362.46 ± 80.47 N), and SA (1,334.52 ± 195.80 N). All backup fixation groups were stronger than the control group with IS fixation only (932.91 ± 99.86 N, P < .001). There was no significant difference in outcome measures between the extramedullary suture button groups with and without the BP (failure loads of 721.39 ± 103.32 N and 718.15 ± 108.61 N, respectively). Conclusions: Subcortical backup fixation in ACL reconstruction has similar biomechanical properties to current methods and is a viable backup fixation alternative. Backup fixation methods work synergistically with IS primary fixation to strengthen the construct. There is no advantage to adding backup fixation to extramedullary button (all-inside) primary fixation when all suture strands are secured to the extramedullary button. Clinical Relevance: This study provides evidence that subcortical backup fixation is a viable alternative for surgeons during ACL reconstruction.

Hooks Versus Pedicle Screws at the Upper Instrumented Level: An In Vitro Biomechanical Comparison.

STUDY DESIGN: Controlled laboratory study. OBJECTIVE: The aim was to compare motions at the upper instrumented vertebra (UIV) and supra-adjacent level (UIV+1) between two fixation techniques in thoracic posterior spinal fusion constructs. We hypothesized there would be greater motion at UIV+1 after cyclic loading across all constructs and bilateral pedicle screws (BPSs) with posterior ligamentous compromise would demonstrate the greatest UIV+1 range of motion. SUMMARY OF BACKGROUND DATA: Proximal junctional kyphosis is a well-recognized complication following long thoracolumbar posterior spinal fusion, however, its mechanism is poorly understood. MATERIALS AND METHODS: Twenty-seven thoracic functional spine units were randomly divided into three UIV fixation groups (n=9): (1) BPS, (2) bilateral transverse process hooks (TPHs), and (3) BPS with compromise of the posterior elements between UIV and UIV+1 (BPS-C). Specimens were tested on a servohydraulic materials testing system in native state, following instrumentation, and after cyclic loading. functional spine units were loaded in flexion-extension (FE), lateral bending, and axial rotation. RESULTS: After cyclic testing, the TPH group had a mean 29.4% increase in FE range of motion at UIV+1 versus 76.6% in the BPS group ( P <0.05). The BPS-C group showed an increased FE of 49.9% and 62.19% with sectioning of the facet joints and interspinous ligament respectively prior to cyclic testing. CONCLUSION: BPSs at the UIV led to greater motion at UIV+1 compared to bilateral TPH after cyclic loading. This is likely due to the increased rigidity of BPS compared to TPH leading to a "softer" transition between the TPH construct and native anatomy at the supra-adjacent level. Facet capsule compromise led to a 49.9% increase in UIV+1 motion, underscoring the importance of preserving the posterior ligamentous complex. Clinical studies that account for fusion rates are warranted to determine if constructs with a "soft transition" result in less proximal junctional kyphosis in vivo .

Biomechanical Analysis of Multilevel Posterior Cervical Spinal Fusion Constructs.

STUDY DESIGN: Controlled Laboratory Study. OBJECTIVE: To compare multilevel posterior cervical fusion (PCF) constructs stopping at C7, T1, and T2 under cyclic load to determine the range of motion (ROM) between the lowest instrumented level and lowest instrumented-adjacent level (LIV-1). SUMMARY OF BACKGROUND DATA: PCF is a mainstay of treatment for various cervical spine conditions. The transition between the flexible cervical spine and rigid thoracic spine can lead to construct failure at the cervicothoracic junction. There is little evidence to determine the most appropriate level at which to stop a multilevel PCF. METHODS: Fifteen human cadaveric cervicothoracic spines were randomly assigned to 1 of 3 treatment groups: PCF stopping at C7, T1, or T2. Specimens were tested in their native state, following a simulated PCF, and after cyclic loading. Specimens were loaded in flexion-extension), lateral bending, and axial rotation. Three-dimensional kinematics were recorded to evaluate ROM. RESULTS: The C7 group had greater flexion-extension motion than the T1 and T2 groups following instrumentation (10.17±0.83 degree vs. 2.77±1.66 degree and 1.06±0.55 degree, P <0.001), and after cyclic loading (10.42±2.30 degree vs. 2.47±0.64 degree and 1.99±1.23 degree, P <0.001). There was no significant difference between the T1 and T2 groups. The C7 group had greater lateral bending ROM than both thoracic groups after instrumentation (8.81±3.44 degree vs. 3.51±2.52 degree, P =0.013 and 1.99±1.99 degree, P =0.003) and after cyclic loading. The C7 group had greater axial rotation motion than the thoracic groups (4.46±2.27 degree vs. 1.26±0.69 degree, P =0.010; and 0.73±0.74 degree, P =0.003) following cyclic loading. CONCLUSION: Motion at the cervicothoracic junction is significantly greater when a multilevel PCF stops at C7 rather than T1 or T2. This is likely attributable to the transition from a flexible cervical spine to a rigid thoracic spine. Although this does not account for in vivo fusion, surgeons should consider extending multilevel PCF constructs to T1 when feasible. LEVEL OF EVIDENCE: Not applicable.

A Case of Periprosthetic Joint Infection Because of Rothia Mucilaginosa.

Periprosthetic joint infection (PJI) is a rare but devastating complication of total joint arthroplasty. Identifying the offending infectious agent is essential to appropriate treatment, and uncommon pathogens often lead to a diagnostic delay. This case describes the first known instance of a total knee arthroplasty (TKA) with Rothia mucilaginosa, a typical respiratory tract organism. This report aims to provide insight into the treatment of this atypical PJI, as there are only six previously published cases of Rothia species PJI septic arthritis. The patient is a 64-year-old diabetic male who underwent a right TKA and left TKA ∼6 months later. Approximately 3 weeks status post-left TKA, he showed evidence of left PJI. One year after treatment and recovery from his left PJI, he presented with several months of right knee pain and fatigue. Subsequent labs and imaging revealed right PJI. No recent history of dental disease or work was observed. He then underwent two-stage revision right knee arthroplasty and microbial cultures yielded Rothia mucilaginosa. After initial empiric treatment, antibiotic therapy was narrowed to 6 weeks of vancomycin. Following negative aspiration cultures the patient underwent reimplantation of right TKA components. One year following treatment, the patient was fully recovered with no evidence of infection. This case emphasizes the possibility of microbial persistence despite various antibiotic treatment regimens for the patient's contralateral knee arthroplasty and PJI. Additionally, this case demonstrates the importance of two-stage revision in patients with PJI, and the viability of treating Rothia species PJIs with vancomycin.

All-Suture Suspensory Button Has Similar Biomechanical Performance to Metal Suspensory Button for Onlay Subpectoral Biceps Tenodesis.

Purpose: To evaluate the maximal load at failure, cyclic displacement, and stiffness of onlay subpectoral biceps tenodesis (BT) with an intramedullary unicortical metal button (MB) versus a unicortical all-suture button (ASB). Methods: Eighteen matched paired human cadaveric proximal humeri were randomly allocated for subpectoral BT with either ASB or MB using a high-strength suture. Specimens were tested on a servohydraulic mechanical testing apparatus under cyclic load for 1,000 cycles and then loaded to failure. The clamp was then adjusted to isolate the suture-anchor point interface and loaded to failure. Maximal load to failure, displacement, and stiffness were compared. Results: There was no significant difference between groups in stiffness, displacement, or yield load. The maximal load to failure for the MB was greater than the ASB (347.6 ± 74.1N vs 266.5 ± 69.3N, P = .047). Eight specimens in each group failed by suture pull-through on the tendon. When the suture-anchor point interface was isolated, there was no significant difference in maximal load at failure (MB 586.5 ± 215.8N vs ASB 579.6 ± 255.9N, P = .957). Conclusions: This study demonstrates that the MB and ASB have similar biomechanical performance when used in subpectoral BT. Although the MB showed statistically significant greater maximal load to failure, there was no difference between the MB and ASB when the suture-tendon interface was eliminated. Suture pull-through was the most common mode of failure for both implants, underscoring the importance of the suture-tendon interface. Clinical Relevance: Fixation techniques for the treatment of long head of the biceps brachii tenodesis continue to evolve. The use of an all-suture suspensory button has advantages, but it is important to understand if this implant is a biomechanically suitable alternative to a metal suspensory button.

The Effect of Preoperative Mental Health Status on Outcomes After Anterior Cervical Discectomy and Fusion.

BACKGROUND: The effect of preoperative mental health on outcomes after anterior cervical discectomy and fusion (ACDF) is of increasing interest. The purpose of this study was to utilize patient-reported outcome measures (PROMs) to compare outcomes after ACDF in patients with and without poor mental health. We hypothesized that patients with worse baseline mental health would report worse outcomes after surgery. METHODS: Patients undergoing ACDF for degenerative cervical spondylosis with at least 12 months of follow-up were included. Outcomes collected before and after surgery included the RAND-36, Neck Disability Index (NDI), EuroQol 5-dimension (EQ-5D), and Single Assessment Numeric Evaluation (SANE) score. RESULTS: Seventy-one patients were included and assigned to the depression or nondepression group based on baseline mental health. The depression group had worse baseline preoperative scores across all PROMs: NDI (44.2 vs 36.8, P = 0.05), RAND (1511.4 vs 2198.18, P < 0.001), EQ-5D (12.55 vs 10.14, P < 0.001), and SANE (56.3 vs 72.9, P < 0.001). Postoperatively, the depression group had worse scores at the final follow-up for RAND (2242.8 vs 2662.2, P = 0.03) and SANE (71.5 vs 80.8, P = 0.02). Both groups experienced improvements with ACDF across all PROMs. The changes in each PROM were not statistically significant between groups. There were no statistically significant differences in the percentage of patients achieving the minimal clinically important difference across PROMs. CONCLUSION: This study is the first to utilize the RAND-36, EQ-5D, NDI, and SANE scores to assess preoperative mental health and its effect on postoperative outcomes after ACDF. While poor preoperative mental health status yielded significantly worse baseline and postoperative outcomes scores, patients experienced significant improvement in symptoms after ACDF. CLINICAL RELEVANCE: Clinicians should be aware of the effects of poor mental health status on clinical outcomes in patients undergoing anterior cervical fusion, but can still expect significant clinical improvements after surgery.

Epidemiology of Meniscus Injuries in the Military Health System and Predictive Factors for Arthroscopic Surgery.

Meniscus injuries occur at a higher rate in the military than the general population. Appropriate management and rehabilitation of meniscus injuries is important for maintaining readiness. The purpose of this study was to describe the health burden of meniscus injuries in the Military Health System (MHS) to identify the surgical intervention rate for meniscus injuries, and to determine which injury characteristics and demographic variables were associated with the likelihood of surgery after injury. The U.S. Department of Defense Management Analysis and Reporting Tool, a database of health care encounters by military personnel and dependents, was queried for encounters associated with a meniscal injury diagnosis between January 1, 2010, and December 31, 2011. Meniscus injuries were categorized into (1) isolated medial, (2) isolated lateral, (3) combined medial and lateral, and (4) unspecified cohorts. Patients under 18 and over 51 years were excluded, as well as patients without records at least 1 year prior to diagnosis or 2 years after. Relevant surgical procedures were identified with the Current Procedural Terminology (CPT) codes for arthroscopic surgery of the knee, meniscus repair, meniscectomy, and anterior cruciate ligament (ACL) reconstruction. There were 2,969 meniscus injuries meeting inclusion criteria during the study period. There were 1,547 (52.1%) isolated medial meniscus injuries, 530 (17.9%) isolated lateral meniscus injuries, 452 (15.3%) involved both menisci, and 435 (14.7%) were unspecified. The mean age was 35.5 years (standard deviation [SD] = 9.3). An adjacent ligamentous injury occurred in 901 patients (30.3%). The treatment course led to arthroscopic surgery in 52.8% (n = 1,568) of all meniscus injuries. Eighty-five percent (n = 385) of combined medial and lateral tears, 54.9% of medial tears, and 51.6% of lateral tears underwent surgery. Partial meniscectomy was the most common procedure performed while 47.2% (n = 1,401) of tears were not treated surgically. Bilateral meniscus injuries had 4.57 greater odds of undergoing knee arthroscopy (95% confidence interval [CI]: 3.46, 6.04), 2.42 times odds of undergoing a meniscus repair, and 4.59 times odds for undergoing a meniscus debridement (95% CI: 3.62, 5.82). The closed nature of the MHS allows reliable capture of surgical rates for meniscus injuries within the military population. Meniscus injuries are common in the military and impose a significant burden on the MHS. Appropriate management and rehabilitation of this injury is important for maintaining readiness.

Intramedullary Unicortical Button and All-Suture Anchors Provide Similar Maximum Strength for Onlay Distal Biceps Tendon Repair.

PURPOSE: To evaluate the biomechanical profile of onlay distal biceps repair with an intramedullary unicortical button versus all-suture anchors under cyclic loading and maximal load to failure. METHODS: Twenty paired fresh-frozen human cadaveric elbows were randomized to onlay distal biceps repair with either a single intramedullary button or with two 1.35-mm all-suture anchors. A 1.3-mm high tensile strength tape was used in a Krackow stitch to suture the tendons in both groups. Specimens and repair constructs were loaded for 3,000 cycles and then loaded to failure. Maximum load to failure, mode of failure, and construct elongation were recorded. RESULTS: Mean (± standard deviation) maximum load to failure for the unicortical intramedullary button and all-suture anchor repairs were 503.23 ± 141.77 N and 537.33 ± 262.13 N (P = .696), respectively. Mean maximum displacement after 3,000 cycles (± standard deviation) was 4.17 ± 2.05 mm in the button group and 2.06 ± 1.05 mm in the suture anchor group (P = .014). Mode of failure in the button group was suture tape rupture in 7 specimens, failure at the tendon-suture interface in 2 specimens, and button pullout in 1 specimen. Anchor pullout was the mode of failure in all suture anchor specimens. There were no tendon ruptures or radial tuberosity fractures in either group. CONCLUSIONS: This study demonstrates that onlay distal biceps repair with 2 all-suture anchors has similar maximum strength to repair with an intramedullary button and that both are viable options for fixation. CLINICAL RELEVANCE: All-suture anchors and unicortical intramedullary button have similar maximum strength at time zero. Both constructs provide suitable fixation for onlay distal biceps repair.

Biomechanical Comparison of Anatomic Restoration of the Ulnar Footprint vs Traditional Ulnar Tunnels in Ulnar Collateral Ligament Reconstruction.

BACKGROUND: Current techniques for ulnar collateral ligament (UCL) reconstruction do not reproduce the anatomic ulnar footprint of the UCL. The purpose of this study was to describe a novel UCL reconstruction technique that utilizes proximal-to-distal ulnar bone tunnels to better re-create the anatomy of the UCL and to compare the biomechanical profile at time zero among this technique, the native UCL, and the traditional docking technique. HYPOTHESIS: The biomechanical profile of the anatomic technique is similar to the native UCL and traditional docking technique. STUDY DESIGN: Controlled laboratory study. METHODS: Ten matched cadaveric elbows were potted with the forearm in neutral rotation. The palmaris longus tendon graft was harvested, and bones were sectioned 14 cm proximal and distal to the elbow joint. Specimen testing included (1) native UCL testing performed at 90° of flexion with 0.5 N·m of valgus moment preload, (2) cyclic loading from 0.5 to 5 N·m of valgus moment for 1000 cycles at 1 Hz, and (3) load to failure at 0.2 mm/s. Elbows then underwent UCL reconstruction with 1 elbow of each pair receiving the classic docking technique using either anatomic (proximal to distal) or traditional (anterior to posterior) tunnel locations. Specimen testing was then repeated as described. RESULTS: There were no differences in maximum load at failure between the anatomic and traditional tunnel location techniques (mean ± SD, 34.90 ± 10.65 vs 37.28 ± 14.26 N·m; P = .644) or when including the native UCL (45.83 ± 17.03 N·m; P = .099). Additionally, there were no differences in valgus angle after 1000 cycles across the anatomic technique (4.58°± 1.47°), traditional technique (4.08°± 1.28°), and native UCL (4.07°± 1.99°). The anatomic group and the native UCL had similar valgus angles at failure (24.13°± 5.86° vs 20.13°± 5.70°; P = .083), while the traditional group had a higher valgus angle at failure when compared with the native UCL (24.88°± 6.18° vs 19.44°± 5.86°; P = .015). CONCLUSION: In this cadaveric model, UCL reconstruction with the docking technique utilizing proximal-to-distal ulnar tunnels better restored the ulnar footprint while providing valgus stability comparable with reconstruction with the docking technique using traditional anterior-to-posterior ulnar tunnel locations. These results suggest that utilization of the anatomic tunnel location in UCL reconstruction has similar biomechanical properties to the traditional method at the time of initial fixation (ie, not accounting for healing after reconstruction in vivo) while keeping the ulnar tunnels farther from the ulnar nerve. Further studies are warranted to determine if an anatomically based UCL reconstruction results in differing outcomes than traditional reconstruction techniques. CLINICAL RELEVANCE: Current UCL reconstruction techniques do not accurately re-create the ulnar UCL footprint. The UCL is a dynamic constraint to valgus loads at the elbow, and a more anatomic reconstruction may afford more natural joint kinematics. This more anatomic technique performs similarly to the traditional docking technique at time zero, and the results of this study may offer a starting point for future in vivo studies.

Coracoid or Clavicle Fractures Associated With Coracoclavicular Ligament Reconstruction.

BACKGROUND: Coracoclavicular (CC) ligament reconstruction is a commonly performed procedure for high-grade acromioclavicular (AC) joint separations. Although distal clavicle and coracoid process fractures represent potential complications, they have been described in only case reports and small case series. PURPOSE: To identify the incidence and characteristics of clavicle and coracoid fractures after CC ligament reconstruction. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: The US Military Health System Data Repository was queried for patients with a Current Procedural Terminology code for CC ligament repair or reconstruction between October 2013 and March 2020. The electronic health records, including patient characteristics, radiographs, operative reports, and clinical notes, were evaluated for intraoperative or postoperative clavicle or coracoid fractures. Initial operative technique, fracture management, and subsequent clinical outcomes were reviewed for these patients. RESULTS: A total of 896 primary CC ligament repairs or reconstructions were performed during the study period. There were 21 postoperative fractures and 1 intraoperative fracture in 20 patients. Of these fractures, 12 involved the coracoid and 10 involved the clavicle. The overall incidence of fracture was 3.81 fractures per 1000 person-years. In 5 patients who sustained a fracture, bone tunnels were not drilled in the fractured bone during the index procedure. A total of 17 fractures were ultimately treated operatively, whereas 5 fractures had nonoperative management. Of the 16 active-duty servicemembers who sustained intraoperative or postoperative fractures, 11 were unable to return to full military duty after their fracture care. CONCLUSION: Fracture of the distal clavicle or coracoid process after CC ligament repair or reconstruction is a rare but serious complication that can occur independent of bone tunnels created during the index procedure. Fractures associated with CC ligament procedures occurred at a rate of 2.46 per 100 cases. Most patients were ultimately treated surgically with open reduction and internal fixation or revision CC ligament reconstruction. Although the majority of patients with intraoperative or postoperative fractures regained full range of motion, complications such as anterior shoulder pain, AC joint asymmetry, and activity-related weakness were common sequelae resulting in physical limitations and separation from military service.

Latarjet After Failed Arthroscopic Bankart Repair Results in Twice the Rate of Recurrent Instability Compared With Primary Latarjet.

PURPOSE: To assess recurrent instability of the shoulder following open Latarjet performed as the primary stabilization procedure or as a salvage procedure. METHODS: A retrospective, comparative cohort study was performed for a consecutive series of patients in the Military Health System who underwent open Latarjet from January 1, 2010, to December 31, 2018. All patients were diagnosed with recurrent anterior shoulder instability and had a minimum of 2 years of postoperative follow-up. Patients were categorized as either having a primary Latarjet (PL; no prior shoulder stabilization procedure) or salvage Latarjet (SL; ≥1 previous arthroscopic surgical stabilization procedures). RESULTS: A total of 234 Latarjet procedures were performed in 234 patients. The overall recurrent instability rate was 15.8% (37/234), the overall reoperation rate was 16.7% (36/234), and the overall complication rate was 14.2% (33/234) over a mean 5.0 years of follow-up. There were 99 PL procedures and 135 SL procedures. The SL group had significantly more recurrent instability than the PL group (SL 28/135, 20.7%; PL 9/99, 9.1%; P = .0158). There was no difference in overall reoperation rates (SL 26/135, 19.3%; PL 13/99, 13.1%; P = .2140) or complication rates (SL 20/135, 14.8%; PL 13/99, 13.3%; P = .9101). CONCLUSION: The rate of recurrent instability following the Latarjet procedure in an active, high-risk population is 15.8%. Primary Latarjet was found to have lower rates of recurrence compared with salvage Latarjet procedures (9.1% versus 20.7%). LEVEL OF EVIDENCE: III.

A Biomechanical Comparison of High-Tensile Strength Tape Versus High-Tensile Strength Suture for Tendon Fixation Under Cyclic Loading.

PURPOSE: To compare the biomechanical properties of high-tensile strength tape and high-tensile strength suture across 2 selected stitch techniques, the Krackow and whip stitch, in securing tendinous tissue during 5,000 cycles of nondestructive loading followed by a load to failure. METHODS: Fourteen matched pairs each of cadaveric Achilles, quadriceps, and patellar tendons (n = 84) were randomly assigned to either Krackow or whip stitch and sutured with either 2-mm high-tensile strength tape or No. 2 high-tensile strength suture. Specimens were preloaded to 20 N, cyclically loaded from 20 to 200 N for 5,000 cycles at 2 Hz, and then loaded to failure at 200 mm/min. Linear mixed models evaluated the effects of suture material and stitch technique on cyclic normalized tendon-suture elongation, total normalized tendon-suture elongation at 5,000 cycles, and maximum load at failure. RESULTS: Across all suture constructs, normalized elongation was greater during the initial 10 cycles, compared with all subsequent cycling intervals (all P < .001). There was less total normalized elongation (ß = -0.239; P = .007) and greater maximum load at failure in tape (ß = 163.71; P = .014) when used in the Krackow stitch compared with the whip stitch. CONCLUSIONS: Our findings indicate that tape used in the Krackow stitch maintains the most favorable fixation strength after enduring cyclic loading, with greater maximum load at failure. In addition, overall normalized elongation during long-term cyclic loading was predominately affected by the stitch technique used, regardless of the suture material; however, tape allowed less normalized elongation during the initial loading cycles, especially when placed in the whip stitch. CLINICAL RELEVANCE: Understanding the potential short- and long-term outcomes of suture material and stitch technique on securing tendinous tissue under repetitive stresses can help inform clinicians on optimal tendon fixation techniques for early postoperative activities.

Cervical Spine Computed Tomography Hounsfield Units Accurately Predict Low Bone Mineral Density of the Femoral Neck.

STUDY DESIGN: A retrospective cohort. OBJECTIVE: The objective of this study to determine the correlation between Hounsfield unit (HU) measurements from the C4 vertebral body and dual-energy x-ray absorptiometry (DXA) T-score. SUMMARY OF BACKGROUND DATA: Recent attention has turned to the utilization of HU measurements from computed tomography (CT) as a potential screening method for low bone mineral density (BMD). We hypothesized that cervical spine CT HU measurements will correlate with BMD measurements conducted with DXA scans of the femoral neck. MATERIAL AND METHODS: Patients with cervical CT and femoral neck DXA scans at 1 institution were included in the study. HUs were manually measured from the cancellous bone in the C4 vertebrae by 1 author blinded to DXA scans. HU measurements were compared with femoral neck DXA T-scores for the entire population. RESULTS: A total of 149 patients with 149 cervical CT and femoral neck DXA scans were included in the study. The low BMD group (osteoporotic and osteopenic combined) showed a significant difference in HU compared with the normal groups within the study (P<0.0001). A low BMD screening value of 447 HU captured over 95% of patients with low BMD within our study and provided a sensitivity of 92% and negative predictive value of 82.1%. The male and female intrasex analysis demonstrated a significant difference between the low BMD and normal BMD groups with P=0.001 and P=0.0001, respectively. CONCLUSIONS: HU measurements taken from the C4 vertebral body on CT scan correlate with low BMD of the femoral neck as determined by DXA scan T-scores. Screening values of 447 HU captured 95% of patients with low BMD, with a high degree of sensitivity, and negative predictive value of 80%. Utilization of cervical spine HU as a screening method provides a simple, quick, and easily assessable screening tool for assessing low BMD. LEVEL OF EVIDENCE: Level III-diagnostic.

Incidence and Characteristics of Humeral Shaft Fractures After Subpectoral Biceps Tenodesis.

BACKGROUND: Biceps tenodesis is a procedure that can address biceps and labral pathology. While there is an increased risk of humeral fracture after biceps tenodesis, it has been described only in case reports. PURPOSE: To identify the incidence, demographics, and characteristics of humeral shaft fractures after biceps tenodesis. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: The US Military Health System Data Repository was searched for patients with a Current Procedural Terminology code for biceps tenodesis between January 2013 and December 2016. The cohort of identified patients was then searched for those assigned a code for humeral fracture per the International Classification of Diseases, 9th Revision and 10th Revision. The electronic health records and radiographs of patients who were diagnosed with a humeral fracture were then evaluated to confirm that the fracture was related to the biceps tenodesis. Records were then reviewed for patient demographics, radiographs, operative reports, and clinical notes. RESULTS: A total of 15,085 biceps tenodeses were performed between January 2013 and December 2016. There were 11 postoperative and 1 intraoperative humeral fractures. The incidence of fracture was <0.1%. All fractures were extra-articular spiral fractures that propagated through the tenodesis site. Eight patients were treated with functional bracing, 3 with open reduction and internal fixation, and 1 with a soft tissue biceps tenodesis revision. Of 8 patients successfully treated nonoperatively, 6 regained full range of shoulder motion. Only 2 of the 4 patients who required operative treatment regained full range of shoulder motion. CONCLUSION: Humeral shaft fracture after biceps tenodesis is a rare complication that occurs in 7.9 out of 10,000 cases. Fractures occurred after various methods of fixation, including suture anchor, cortical button, and interference screw. Most patients were initially treated nonoperatively, and those who healed usually achieved full range of motion; however, those who required operative intervention often had restricted range of motion on final follow-up. Future studies should determine risk factors for fracture after biceps tenodesis.

The Use of Distal Ulnar Hounsfield Units to Predict Future Fragility Fracture Risk.

PURPOSE: Distal ulnar Hounsfield unit (HU) measurements obtained from computed tomography (CT) scans of the wrist can be used to accurately screen for low bone mineral density. It is unknown whether HU measurements can also predict the risk of future fragility fractures. Therefore, the purpose of this study was to determine if the HU values of the distal ulna correlate to fragility fracture risk. METHODS: An electronic database of radiographs at a single institution was searched for all wrist CT scans, obtained for any reason, between January 1, 2002, and December 31, 2008, to allow a minimum of 5-year follow-up. Manual measurement of HU on sequential coronal CT slices of the distal ulnar head was taken, and mean values were recorded. Previously determined cutoff values for the diagnosis of low bone mineral density were implemented to stratify patients as at risk or not at risk for future fragility fracture. Medical records were then manually reviewed for the occurrence of any future fragility fracture (hip, spine, proximal humerus, or rib). RESULTS: There were 161 CTs in 157 patients and 34 fragility fractures in 21 patients, with a prevalence of 13.4%. The mean HU in the fragility fracture group was significantly lower (134.2 vs 197.1 HU). The percentage of low HU patients with fragility fractures was significantly higher (22.7% vs 3.8%). The odds ratio for fragility fracture in the low HU group was 7.4 (95% confidence interval, 2.1-26.2). Using previously determined cutoff values, the sensitivity and specificity of distal ulna HU values for identifying patients who would sustain at least 1 future fragility fracture were 85.7% and 55.2%, respectively. CONCLUSIONS: Patients with low distal ulnar HU were significantly more likely to sustain a subsequent fragility fracture. A determination of distal ulnar HUs represents a quick, simple tool to identify patients potentially at risk for fragility fractures. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.