Midfoot Fusion Using Superconstructs for the Charcot Foot: Current Techniques and Complications.

Neuroarthropathy of the foot and ankle presents a series of challenges. The treating physician faces a perfect storm of pathomechanics, deformity, and medical comorbidities. Successful treatment requires a systematic approach in diagnosis, nonsurgical management, surgical management, and long-term maintenance of the affected extremity. Nonsurgical care of the Charcot foot remains the mainstay of treatment and is successful in most cases. Surgery has become more accepted for patients with severe deformity. The concept of a superconstruct has been introduced to describe modern surgical techniques and implants that have been developed since the early 2000s where stability and durability are maximized. A superconstruct is defined by four factors: (1) fusion is extended beyond the zone of injury to bridge the area of bony dissolution; (2) aggressive bone resection is performed to allow for adequate reduction of deformity without undue tension on the soft-tissue envelope; (3) stronger implants are used than for nonneuropathic fusion procedures, including some specifically developed for fixation of the Charcot foot; and (4) the devices are applied in a position that maximizes mechanical stability to allow the implants to become load sharing. It is important to review the current techniques and implants used in fusion of the neuropathic midfoot and discuss the expected outcomes and complications based on the authors' experience.

Static stability of novel uncemented elbow hemiarthroplasty stabilized with ligament reconstruction.

BACKGROUND: The purpose of this study was to create a model to simulate treatment of unreconstructable distal humerus fractures with hemiarthroplasty. Stability was restored with a latest plate-system that simultaneously tensions medial and lateral collateral ligament grafts. MATERIALS AND METHODS: Static varus and valgus elbow stability was tested in 11 cadaver elbows with intact ligaments and capsule at 5 flexion angles (0°, 30°, 60°, 90°, 120°). The elbows were then destabilized via release of all ligaments and capsular attachments. The distal humerus articular cartilage was excised and replaced with an uncemented hemiarthroplasty. Ligament reconstruction was subsequently performed, and elbow stability was measured and compared to the native state. Dimensions of the hemiarthroplasty component were compared to native elbow dimensions to assess and quantify any existing relationship to elbow stability. RESULTS: A hemiarthroplasty was implanted in all specimens. A size mismatch occurred between the distal humerus trochlea and the olecranon fossa in all specimens and averaged 6.3 mm. Following ligament reconstruction, specimens reproduced the flexion angle-dependent stability of native elbows to both varus and valgus stress. On the medial side, elbow joint stability in mid-flexion was approximately 7% tighter after hemiarthroplasty. Laterally, the elbow was approximately 15% tighter after hemiarthroplasty and demonstrated peak stability in full flexion. The 3 assessed hemiarthroplasty components and bony dimensions did not exhibit any relationship between implant-bone mismatch and elbow stability after ligamentous reconstruction. CONCLUSION: Cadaveric elbow specimens underwent uncemented hemiarthroplasty with soft tissue stabilization with a novel technique for ligament reconstruction. Following hemiarthroplasty and ligament reconstruction, these specimens maintained secure fixation between ligament and bone. Static stability was maintained at varying degrees of elbow flexion regardless of variable mismatch between the hemiarthroplasty component and the native olecranon fossa.

Do Intramedullary Screws Provide Adequate Fixation for Humeral and Ulnar Components in Total Elbow Arthroplasty? A Cadaveric Analysis.

PURPOSE: The objective of this study was to determine the structural properties of the cadaver bone-screw interface for cementless intramedullary screw fixation in the context of total elbow arthroplasty. METHODS: The intramedullary canals of seven humerus and seven ulna specimens from fresh-frozen cadavers were drilled using custom drill bits until the inner cortex was reached and then hand tapped for the corresponding thread size. Titanium screws were advanced into the tapped holes until securely seated. The bones were potted and then mounted on a uniaxial material testing machine. A tensile load was applied, and end-of-test elongation, failure load, energy absorbed, and stiffness were determined. End-of-test load and elongation were defined as the elongation and load experienced by the structure at 3,000 N or failure. Each specimen was inspected for evidence of pullout, loosening, or visible fractures. RESULTS: The end-of-test load and elongation for the humerus specimens were 2721 ± 738 N and 3.0 ± 0.9 mm, respectively. The ulna specimens reached 92% of the humerus specimens' end-of-test load at 2,514 ± 678 N and 120% of their end-of-test elongation (3.6 ± 0.6 mm). The stiffness of the humerus specimens was 1,077 ± 336 N/mm, which was 1.3 times greater than the stiffness of the ulna specimens (790 ± 211 N/mm). Lastly, the energy absorbed by the humerus samples was 3.6 ± 1.6 J, which was 92% of the energy absorbed by the ulna samples at 3.9 ± 1.1 J. One humerus and three ulnas failed before the end-of-test load of 3,000 N. Two failures were caused by screw pullout and two by bone fracture. CONCLUSIONS: Our findings demonstrate that intramedullary screw fixation is successful in withstanding forces that are greater than required for osseointegration. CLINICAL RELEVANCE: Uncemented fixation may be beneficial in elbow arthroplasty.

The spin move to facilitate antegrade coronoid fixation in terrible triad injuries.

BACKGROUND: The role of the coronoid process in elbow instability has been established. When necessary, coronoid fixation can be challenging. Placing fixation perpendicular to the fracture requires achieving a trajectory as close as possible to the midline axis of the proximal ulna, either from anterior to posterior or vice versa. The aim of this study was to determine whether coronoid exposure-and the ability to place fixation from anterior to posterior-is improved via a lateral extensor-splitting approach with forearm supination, that is, the "spin move," with progressive stages of lateral elbow instability. METHODS: The lateral extensor-splitting approach was performed on 9 cadaveric upper extremities. A 0.157-mm (0.062-inch) wire was drilled perpendicularly into the lateral aspect of the humerus just proximal to the lateral epicondyle. A second wire was drilled into the tip of the coronoid, aiming for a drill trajectory as close as possible to the midline axis. The angle between the 2 wires was measured as the initial angle. Three stages of progressive lateral elbow instability were produced by sequential release of the lateral ulnar collateral ligament (LUCL), common extensor origin (CEO), and posterior capsule. At each stage, the spin move was performed and the angle between the 2 wires was measured. The difference between this angle and the initial angle was calculated, with the average value reported as the Δ angle for each stage. The average difference between each stage and the next stage was reported. RESULTS: The spin move resulted in Δ angles of 10.3° with the LUCL released, 20° with the CEO released, and 29.1° with the posterior capsule released. Progressing from LUCL release to CEO release to posterior capsule release, the Δ angle between the K-wires increased an average of 9.6° from the LUCL stage to the CEO stage and 9.1° from the CEO stage to the posterior capsule stage. CONCLUSION: The spin move is a simple maneuver that can improve exposure of the coronoid process regardless of the degree of elbow instability. This may facilitate a more perpendicular screw, bone tunnel, or suture anchor trajectory via the lateral approach, reducing the need for posterior-to-anterior fixation. The improved exposure is inferred from the differences in the K-wire angles with and without the spin move. This study has also quantified the change in coronoid exposure using the angles of the wires with progressive release of the LUCL, CEO, and posterior capsule. If necessary, releasing the CEO or posterior capsule with eventual repair may allow improved coronoid fixation from the lateral approach.

Life Cycle Assessment in Orthopedics.

Covid-19 has led to an increase in the use of PPE, gowns, masks, sanitizers, air circulators, and much more, all contributing to an increase in medical waste. Waste generation is one issue. Emissions are another. The two are linked because waste and emissions are both indicators of consumption. However, waste is not the biggest driver of environmental emissions for healthcare. It is the production of medical equipment, particularly disposables that have a bigger impact. Energy use during care, including heating and cooling our facilities, is another. Environmental emissions like greenhouse gases may not correlate with waste generation, especially if the waste is plastic. Carbon is stored in plastic. Unless you're burning plastic, you're not emitting carbon. Healthcare has a waste issue and healthcare has an emissions issue. They are not necessarily the same thing, however, the strategies to mitigate each overlap. Life cycle assessment quantifies emissions from the creation to disposal of medical supplies. This allows the medical community to make informed choices with respect to the methods and materials that are used in providing care. As other specialties take the lead in reducing their environmental footprint, so too, must orthopedic surgery.

Hand and Wrist Problems That Can Be Deceptive: Avoiding Snakes in the Grass.

In this chapter, the authors describe hand conditions that can be "bad actors" and provide specific clues to identify these problems, and strategies to assess and successfully treat them. We will review pediatric and adult hand fractures, fractures of the distal radius, and trigger digits.

Investigating the effects of Pirfenidone on TGF-ß1 stimulated non-SMAD signaling pathways in Dupuytren's disease -derived fibroblasts.

BACKGROUND: Dupuytren's disease (DD) is a progressive, debilitating condition of the hand that can eventually cause contractures of the affected fingers. Transforming growth factor- ß1 (TGF-ß1) has been reported to play a key role in DD pathology. Increased expression of TGF-ß1 has shown to be the main stimulator of myofibroblast activity and in DD contractures. Pirfenidone (PFD), a small active molecule possess the ability to inhibit TGF-ß1-mediated action in various fibrotic disorders. Our recent published findings show that PFD reduced TGF-ß1-mediated cellular functions implicated in DD through SMAD signaling pathways. In the present study, the effect of PFD on TGF-ß1-mediated non-SMAD signaling pathways were investigated in both carpal tunnel (CT) - and DD-derived fibroblasts. METHODS: Fibroblasts harvested from Dupuytren's disease (DD) and carpal tunnel (CT) tissues were cultured in the presence or absence of TGF-ß1 (10 ng/ml) and/or PFD (800 µg/ml). Cell lysates were analyzed using Western blots. Equal amounts of proteins were loaded to determine the phosphorylation levels of phosphatidylinositol-3 kinase (PI3K/AKT), extracellular regulated kinases (ERK1/2), p38 mitogen-activated protein kinase and Rho family related myosin light chain (MLC). RESULTS: We show that the TGF-ß1-induced phosphorylation of AKT was significantly decreased by the addition of PFD (800 µg/mL) in both CT- and DD-derived fibroblasts. Interestingly, there was no significant difference in the phosphorylation levels of both ERK and p38 on TGF-ß1- induced cells in both CT-and DD-derived fibroblasts. But, PFD significantly decreased the TGF- ß1-induced phosphorylation levels of ERK1/2 in both CT- and DD- cells. In contrast, PFD significantly decreased the basal and TGF- ß1-induced phosphorylation levels of p38 in DD-derived fibroblasts. TGF- ß1-induced phosphorylation levels of MLC was decreased by PFD in DD-derived fibroblasts. CONCLUSIONS: These in-vitro results indicate for the first time that PFD has the potential to inhibit TGF-ß1-induced non-SMAD signaling pathways in both CT- and DD-derived fibroblasts but pronounced statistically significant inhibition on all molecules was observed only in DD-derived fibroblasts. Our previous studies show that PFD can inhibit TGF-ß1- induced SMAD signaling pathway proteins, namely p- SMAD2/SMAD3. These broad and complementary actions suggest PFD as a promising candidate to inhibit the TGF-ß1- mediated molecular mechanisms leading to DD fibrosis.

The naked capitellum: a surgeon's guide to intraoperative identification of posterolateral rotatory instability.

HYPOTHESIS: This study's purpose was to provide a reproducible way for surgeons to intraoperatively assess the elbow's lateral ulnar collateral ligament origin and determine whether there is posterolateral rotatory instability (PLRI) despite an intact common extensor origin (CEO). We hypothesized that we could re-create clinically relevant disruption of lateral supporting structures despite an intact CEO and illustrate progressive elbow PLRI. METHODS: The relationship of the lateral capsule to the capitellum articular surface was noted in 8 cadaveric upper extremities. The lateral capsule and extensor origin were sequentially sectioned at 4 stages: intact, release to the lateral epicondyle, release of the posterior capsular insertion, and release of the CEO. Posterior and lateral translation of the radial head (RH) relative to the capitellum was measured with the forearm in extension and supination. RESULTS: The average specimen age was 78.9 years. The lateral capsule originated within 1 to 2 mm of the capitellum articular surface. Lateral capsular sectioning to the 6-o'clock position of the lateral epicondyle created an unstable elbow with posterior and lateral RH translation. Sequential sectioning of the posterior capsular insertion created significant additional RH translation posteriorly (P < .05). With release of the capsule and the extensor origin, the elbow was grossly unstable. CONCLUSIONS: The elbow's lateral capsuloligamentous complex plays an important role in preventing PLRI. Larger degrees of elbow laxity are associated with further peel back of the capsuloligamentous complex despite an intact CEO. The surgeon must retract the extensor origin intraoperatively to assess for lateral ulnar collateral ligament and/or lateral capsule disruption to prevent a missed case of PLRI.

The diagnostic clinical value of thumb metacarpal grind, pressure-shear, flexion, and extension tests for carpometacarpal osteoarthritis.

STUDY DESIGN: Clinical measurement. INTRODUCTION: Common provocative maneuvers to differentiate thumb carpometacarpal (CMC) osteoarthritis from other sources of pain are the grind, metacarpal (MC) flexion, and MC extension tests. A maneuver known as the pressure-shear test is described here. PURPOSE OF THE STUDY: To compare the diagnostic value of the grind, metacarpal flexion, metacarpal extension, and pressure-shear tests for CMC osteoarthritis of the thumb. METHODS: The diagnostic accuracy of each test was compared in 127 thumbs from 104 patients. Sensitivity, specificity, and predictive values of each test were calculated. In a secondary analysis, polychoric correlation coefficients were used to assess the correlation of each test with severity defined by Eaton-Littler stage. RESULTS: The overall diagnostic accuracy of the thumb MC grind, pressure-shear, flexion, and extension tests were 70%, 98%, 47%, and 55%, respectively. The sensitivities were 64%, 99%, 36%, and 46%, respectively, and specificities were 100%, 95%, 100%, and 100%, respectively. For the diagnosis of Thumb CMC arthritis, the MC pressure-shear test was superior overall in terms of overall diagnostic accuracy and sensitivity, while having comparable specificity to the other maneuvers. CONCLUSION: The pressure-shear test was found to be superior to the commonly used grind maneuver and the provocative maneuvers of MC flexion and extension tests to confirm diagnosis of CMC osteoarthritis.

Anti-fibrotic action of pirfenidone in Dupuytren's disease-derived fibroblasts.

BACKGROUND: Dupuytren's disease (DD) is a complex fibro-proliferative disorder of the hand that is often progressive and eventually can cause contractures of the affected fingers. Transforming growth factor beta (TGF-ß1) has been implicated as a key stimulator of myofibroblast activity and fascial contraction in DD. Pirfenidone (PFD) is an active small molecule shown to inhibit TGF-ß1-mediated action in other fibrotic disorders. This study investigates the efficacy of PFD in vitro in inhibiting TGF-ß1-mediated cellular functions leading to Dupuytren's fibrosis. METHODS: Fibroblasts harvested from (DD) and carpal tunnel (CT)- tissues were treated with or without TGF-ß1 and/or PFD and were subjected to cell migration, cell proliferation and cell contraction assays. ELISA; western blots and real time RT-PCR assays were performed to determine the levels of fibronectin; p-Smad2/Smad3; alpha-smooth muscle actin (α-SMA), α2 chain of type I collagen and α1 chain of type III collagen respectively. RESULTS: Our results show that PFD effectively inhibits TGF-ß1-induced cell migration, proliferation and cell contractile properties of both CT- and DD-derived fibroblasts. TGF-ß1-induced α-SMA mRNA and protein levels were inhibited at the higher concentration of PFD (800 µg/ml). Interestingly, TGF-ß1 induction of type I and type III collagens and fibronectin was inhibited by PFD in both CT- and DD- derived fibroblasts, but the effect was more prominent in DD cells. PFD down-regulated TGF-ß1-induced phosphorylation of Smad2/Smad3, a key factor in the TGF-ß1 signaling pathway. CONCLUSION: Taken together these results suggest the PFD can potentially prevent TGF-ß1-induced fibroblast to myofibroblast transformation and inhibit ECM production mainly Type I- and Type III- collagen and fibronectin in DD-derived fibroblasts. Further in-vivo studies with PFD may lead to a novel therapeutic application in preventing the progression or recurrence of Dupuytren's disease.

Developing an animal model of Dupuytren's disease by orthotopic transplantation of human fibroblasts into athymic rat.

BACKGROUND: Dupuytren's disease (DD) is a slow, progressive fibroproliferative disorder affecting the palms of the hands. The disease is characterized by the formation of collagen rich- cords which gradually shorten by the action of myofibroblasts resulting in finger contractures. It is a disease that is confined to humans, and a major limiting factor in investigating this disorder has been the lack of a faithful animal model that can recapitulate its distinct biology. The aim of this study was to develop such a model by determining if Dupuytren's disease (DD)- and control carpal tunnel (CT)-derived fibroblasts could survive in the forepaw of the nude rats and continue to exhibit the distinct characteristics they display in in vitro cultures. METHODS: 1x10(7) fluorescently labeled DD- and CT-derived fibroblasts were transplanted into the left and right forepaws of nude rats respectively. Cells were tracked at regular intervals for a period of two months by quantifying emitted fluorescent signal using an IVIS imaging system. After a period of 62 days rat forepaw connective tissues were harvested for histology and total RNA was isolated. Human-specific probes were used to perform real time RT-PCR assays to examine the expression patterns of gene products associated with fibrosis in DD. Rat forepaw skin was also harvested to serve as an internal control. RESULTS: Both CT- and DD-derived fibroblasts survived for a period of 62 days, but DD-derived cells showed a significantly greater level of persistent fluorescent signal at the end of this time than did CT-derived cells. mRNA expression levels of α-smooth muscle actin (α-SMA), type I- and type III- collagens were all significantly elevated in the forepaw receiving DD cord-derived fibroblasts in comparison to CT-derived fibroblasts. Masson's trichrome stain confirmed increased collagen deposition in the forepaw that was injected with DD cord-derived fibroblasts. CONCLUSIONS: For the first time we describe an animal model for Dupuytren's disease at the orthotopic anatomical location. We further show that gene expression differences between control (CT) and diseased (DD) derived fibroblasts persist when these cells are transplanted to the forepaw of the nude rat. These preliminary findings indicate that, with further refinements, this animal model holds promise as a baseline for investigating novel therapeutic regimens to determine an effective strategy in treating DD.

The Palpable Scaphoid Surface Area in Various Wrist Positions.

PURPOSE: To determine the theoretical amount of surface area available for palpation of the scaphoid in various wrist positions and to provide a guide depicting which wrist position will expose proximal pole, waist, and distal pole fractures. METHODS: Using 3 fresh-frozen male cadaver wrists, we digitized palpable surface areas (dorsal, volar, and snuffbox) of the scaphoid in several wrist positions. The entire scaphoid was then excised and a digitized 3-dimensional reconstruction of the entire scaphoid was obtained. The 2 images were superimposed and the surface area was calculated RESULTS: The maximum palpable area of the scaphoid was achieved with the wrist in neutral extension and maximum ulnar deviation and the wrist in maximum flexion and neutral deviation. Neutral wrist extension and ulnar deviation exposed all but the most proximal portion of the proximal pole and the distal pole, which made this the ideal position to detect tenderness from a scaphoid waist fracture and larger proximal pole fractures. Maximum wrist flexion with neutral wrist deviation exposed the entire proximal pole, which made this the ideal position to detect tenderness from a proximal pole scaphoid fracture. CONCLUSIONS: Wrist position influences the amount of scaphoid surface area available for palpation and should be considered when examining a patient with a suspected scaphoid fracture. CLINICAL RELEVANCE: The scaphoid should be palpated in 3 anatomic regions with the wrist placed in different positions to maximally expose the anatomical region being palpated.

Arthroscopically assisted elbow interposition arthroplasty without hinged external fixation: surgical technique and patient outcomes.

BACKGROUND: Total elbow arthroplasty is successful in older, lower demand patients but not in the younger, more active individual with severe elbow arthritis. Interposition arthroplasty is an alternative for younger patients who hope to minimize the degree to which arm use is restricted. Interposition arthroplasty traditionally involves release of all ligaments and capsule. As a result, the postoperative care included the use of a hinged external fixator of the elbow to apply distraction and to permit motion during the early phases of healing. We describe a novel surgical technique without a hinged external fixator that allows secure fixation of the interposition graft through arthroscopic assistance and maintains the integrity of the medial collateral ligament with only a takedown and repair of the lateral collateral ligament complex. METHODS: A retrospective chart review was performed to analyze 4 patients with an average age of 57 years who underwent surgery between 2007 and 2011. The patients were also contacted to assess elbow-specific American Shoulder and Elbow Surgeons and Disabilities of the Arm, Shoulder, and Hand scores. RESULTS: The average follow-up was 3.6 years (range, 2.5-6 years), and 1 patient was converted to a total elbow arthroplasty after 2.5 years because of persistent pain. The remaining 3 patients have done well with regard to pain control, stability, and functional use of the operative extremity. There were no postoperative complications. DISCUSSION: On the basis of our small series of patients, an arthroscopically assisted elbow interposition arthroplasty without hinged external fixation can provide satisfactory medium-term outcomes as a salvage procedure for a difficult condition with limited options.

Characterization of Unpublished Manuscripts by Applicants to an Orthopedic Hand Surgery Fellowship.

Purpose: Obtaining a hand surgery fellowship is becoming increasingly competitive, and research is an important factor when assessing applications. Given the competitive nature of the fellowship application process, applicants may feel the need to bolster their application by misrepresenting their research experience. One form of misrepresentation rarely discussed in prior studies is the listing of submitted works under a "Publications" heading in curricula vitae. This study examines the prevalence of misclassification of manuscripts by applicants to a hand surgery fellowship and identifies factors that might be associated with incorrect classification. Methods: A retrospective review of 122 applicants to the 2020-2021 cycle for hand surgery fellowship was performed. Names and identifiable information were redacted prior to review. Demographic data collected included sex, United States Medical Licensing Examination Step 1 score, medical school rank, residency specialty, total publications, presence of submitted manuscripts in the "Publications" section, total number of submitted manuscripts, and total published abstracts and poster presentations. Results: A total of 1,098 listed publications across the 122 applicants were reviewed with a median of five publications per applicant. Submitted manuscripts were listed as publications by 33 applicants (27%). No observable differences by age, United States Medical Licensing Examination Step 1 score, or total number of publications were seen. Misclassification rates were not associated with publication totals. Conclusions: More than one-quarter of applicants incorrectly listed submitted or unaccepted manuscripts as publications. It is our hope that making fellowship applicants aware of this issue will decrease the rates of misrepresentation in future application cycles. Clinical relevance: The competition for hand surgery fellowships has become more intense, and this may explain our finding that 27% of applicants misrepresent the status of research on hand surgery fellowship applications.

Polymethyl Methacrylate for Elbow Arthroplasty: Is There Another Way?

Polymethyl methacrylate remains the only US Food and Drug Administration-approved method of total elbow arthroplasty fixation and exhibits high aseptic loosening rates that result in challenging revision surgeries and potential morbidity secondary to bone-cement implantation syndrome. In this policy paper, the authors aim to explore the historical background of polymethyl methacrylate and the complications that arise in association with its use. We will review arthroplasty trends in the elbow and lower extremities and the challenges with the US Food and Drug Administration-approval process.

Elbow Uncemented Hemiarthroplasty: Surgical Technique.

Management of elbow arthritis in younger and higher demand patients is challenging and may benefit from a distal humerus hemiarthroplasty that employs a noncemented method of implant fixation and stabilizes the elbow through ligament reconstruction. By not replacing both articulating surfaces, hardware longevity may be improved. We describe a novel system that may be indicated for the treatment of posttraumatic or primary osteoarthritis of the distal humerus. The step-by-step technique for surgical implantation of this uncemented distal humerus hemiarthroplasty is described and illustrated.

Elbow arthritis: current concepts.

Elbow arthritis is a debilitating condition manifesting as a painful, stiff elbow. The purpose of this article is to provide an update and analyze current management, treatment options, and outcomes of treatment for elbow arthritis. This article focuses on recent developments in the treatment for elbow arthritis. Nonsurgical management may provide symptomatic relief in the majority of patients in the early stages of the disease process. Surgical treatment is guided by disease etiology and severity, patient age, and functional demands. Arthroscopic or open synovectomy, debridement arthroplasty, and interposition arthroplasty are generally recommended for the young and active patient population, whereas for low-demand and elderly patients with end-stage painful arthritis, total elbow arthroplasty is considered a more suitable surgical option. Advances in arthroscopic techniques and implant design have led to substantial improvements in the treatment of elbow arthritis.

Computed Tomography-Based Templating of Proximal Ulna Intramedullary Screw Fixation.

BACKGROUND: Intramedullary screw fixation of the proximal ulna can be used for fixation of the ulnar component in total elbow arthroplasty. Our purpose was to use computed tomography (CT) to characterize proximal ulna anatomy with respect to intramedullary screw fixation, and then to validate this templating process by inserting intramedullary screws into 3-dimensional (3D)-printed models. METHODS: Thirty elbow CT scans were reformatted in the axis of the proximal ulna. Screw placement was templated by fixing a length at 78 mm distal to the centerline of ulnohumeral rotation and measuring diameter, and then fixing the screw pitch diameter to 5.5 mm and measuring length. Three-dimensional models were printed for 5 patients, and intramedullary screws were advanced as distal as possible until endosteal fit was achieved. RESULTS: All patients had an anatomic limit for intramedullary screw fixation, due to dorsal angulation, varus angulation, or both. At 78 mm distal to the centerline of rotation, mean screw diameter was 5.4 mm (range, 3.2-8.0). When fixing screw diameter to 5.5 mm, the mean screw length was 79.9 mm (range, 64.2-107.9). All intramedullary screws were placed in the 3D models within 3 mm of the templated length, with correlation coefficient 0.992. CONCLUSION: This study characterized proximal ulna anatomy in the context of intramedullary screw fixation. Templating allows surgeons to predict intramedullary screw sizing, and a broad range of screw lengths and diameters is required when attempting intramedullary screw fixation for placement of the ulnar component in uncemented total elbow arthroplasty.

Comparing Static Stability of Native Elbow With Static Stability of Novel Bidirectional Ligament Reconstruction at Different Degrees of Elbow Flexion.

Purpose: The treatment of bidirectional ligament instability is proposed using a method that simultaneously tensions medial and lateral ligaments. Graft tension is maintained via plates that apply compression between the graft and bone. Methods: We tested static varus and valgus elbow stability in six cadaver elbows with intact ligaments and capsules at five positions, and then created gross instability by dividing all soft tissue attachments. A ligament reconstruction was subsequently performed with and without nonabsorbable ligament augmentation. Elbow stability was measured and compared with the native state. Results: The augmented and the nonaugmented ligament reconstructions provided stability to the lateral side with only 1.0 mm of increased deflection recorded for the augmented ligaments and 0.6 mm for the nonaugmented when compared with the native state. On the medial side, the deflection was greater after reconstruction compared with the native state with the augmented ligaments ranging between 1.0 and 1.8 mm and the nonaugmented ligament reconstruction ranging between 2.4 and 3.3 mm. Conclusions: This novel ligament reconstruction maintained secure fixation between ligament and bone and allowed for maintenance of static stability at different degrees of elbow flexion. Clinical Relevance: Restoring elbow stability using a method that minimizes ligament graft and which may not need to be removed could benefit management of bidirectionally unstable elbows, such as following interposition arthroplasty or substantial trauma.

Radial head replacement with a bipolar system: a minimum 2-year follow-up.

BACKGROUND: We report the short-term results of a cohort of patients undergoing radial head replacement using a novel radial head prosthesis with a smooth, unfixed, telescoping stem and a bipolar design after a mean follow-up of 34 months (range, 24-48 months). MATERIALS AND METHODS: Patients were assessed using clinical and radiographic examination as well as with standardized outcome measures. Thirty implants (29 patients) were available for review. RESULTS: At final follow-up, the average Mayo Elbow Performance Index Score was 92.1 and the Disabilities of the Arm, Shoulder, and Hand Score was 13.8. Clinical examination revealed significant differences between operative and nonoperative sides for flexion/extension and pronation/supination. Radiographic measurement of medial and lateral ulnohumeral spaces revealed re-establishment of a congruent elbow joint. No significant arthritic changes were identified at the radiocapitellar joint. Minimal angular migration of the implant in the proximal radial shaft was observed over time. Complications included 1 patient requiring temporary placement of a hinged external fixator for instability and 1 patient requiring revision surgery at 4 weeks. CONCLUSION: This review demonstrates that a bipolar radial head prosthesis with a smooth stem and telescoping neck effectively restores stability to elbows with a comminuted radial head fracture and valgus instability. To date, this is the largest reported outcome analysis of bipolar radial head replacement in the literature.