Comparing the volume of vascular intersection of two femoral neck fracture fixation implants using an In silico technique.

Femoral neck fracture displacement with subsequent vascular disruption is one of the factors that contribute to trauma-induced avascular necrosis of the femoral head. Iatrogenic damage of the intraosseous arterial system during fixation of femoral neck fracture is another possible cause of avascular necrosis that is less well understood. Recently, Zhao et al (2017) reconstructed 3D structures of intraosseous blood supply and identified the epiphyseal and inferior retinacular arterial system to be important structures for maintaining the femoral head blood supply after femoral neck fracture. The authors therefore recommended placing implants centrally to reduce iatrogenic vascular injuries. Our in vitro study compared the spatial footprint of a traditional dynamic hip screw with an antirotation screw versus a newly developed hip screw with an integrated antirotation screw on intraosseous vasculature. Methods: Three dimensional (3D) µCT angiograms of 9 cadaveric proximal femora were produced. Three segmented volumes-porous or cancellous bone, filled or cortical bone, and intraosseous vasculature-were converted to surface files. 3D in silico models of the fixation systems were sized and implanted in silico without visibility of the vascular maps. The volume of vasculature that overlapped with the devices was determined. The ratio of the vascular intersection to the comparator device was calculated, and the mean ratio was determined. A paired design, noninferiority test was used to compare the devices. Results: Results indicate both significant (P < 0.001) superiority and noninferiority of the hip screw with an integrated antirotation screw when compared with a dynamic hip screw and antirotation screw for the volume of vasculature that overlapped with each device in the femoral neck. Conclusions: Combining established methods of vascular visualization with newer methods enables an implant's impact on vascular intersection to be assessed in silico. This methodology suggests that when used for femoral neck fracture management, the new device intersects fewer blood vessels than the comparator. Comparative clinical studies are needed to investigate whether these findings correlate with the incidence of avascular necrosis and clinical outcomes.

Examination of Skill Acquisition and Grader Bias in a Distal Radius Fracture Fixation Model.

OBJECTIVES: Primary: Assess the ability of faculty graders to predict the objectively measured strength of distal radius fracture fixation. Secondary: Compare resident skill variation and retention related to other knowable training data. DESIGN: Residents were allowed 60 minutes to stabilize a standardized distal radius fracture using an assigned fixed-angle volar plate. Faculty observed and subjectively graded the residents without providing real-time feedback. Objective biomechanical evaluation (construct strength and stiffness) was compared to subjective grades. Resident-specific characteristics (sex, PGY, and ACGME case log) were also used to compare the objective data. SETTING: A simulated operating room in our laboratory. PARTICIPANTS: Post-graduate year 2, 3, 4, and 5 orthopedic residents. RESULTS: Primary: Faculty were not successful at predicting objectively measured fixation, and their subjective scoring suggests confirmation bias as PGY increased. Secondary: Resident year-in-training alone did not predict objective measures (p = 0.53), but was predictive of subjective scores (p < 0.001). Skills learned were not always retained, as 29% of residents objectively failed subsequent to passing. Notably, resident-reported case-specific experience alone was inversely correlated with objective fixation strength. CONCLUSIONS: This testing model enabled the collection of objective and subjective resident skill scores. Faculty graders did not routinely predict objective measures, and their subjective assessment appears biased related to PGY. Also, in vivo case volume alone does not predict objective results. Familiar faculty teaching consistency, and resident grading by external faculty unfamiliar with tested residents, might alter these results.

Pilot report: non-operative treatment of Mayo Type II olecranon fractures in any-age adult patient.

BACKGROUND: We report on the non-operative treatment of Mayo Type II olecranon fractures. METHODS: Fourteen isolated Mayo Type II olecranon fractures were treated non-operatively, followed to discharge, and retrospectively reviewed. Treatment was splinting in extension followed by protected active motion beginning 3 weeks to 4 weeks post-injury. Mayo Elbow Performance Index (MEPI) and Shortened Disabilities of the Arm, Shoulder and Hand (QuickDASH) scores were available in 86% and 64% of cases, respectively. Follow-up radiographs were obtained. RESULTS: At discharge, the mean (SD) MEPI score was 95 (5). The mean (SD) elbow motion arc was 121° (21°). One patient re-fractured his elbow after discharge by falling on the ice. He recovered after open reduction and internal fixation. One patient (documented Marfan syndrome) developed an asymptomatic non-union. Excepting the patient who fell, no patient received additional care. CONCLUSIONS: In this pilot report, Mayo Type II olecranon fractures were treated non-operatively to discharge. Good to excellent results were obtained in all patients according to the MEPI. Supportive care of these fractures should be comparatively studied. A downside risk to providing supportive care for these fractures was not identified.

Objective Structured Assessments of Technical Skills (OSATS) Does Not Assess the Quality of the Surgical Result Effectively.

BACKGROUND: Performance assessment in skills training is ideally based on objective, reliable, and clinically relevant indicators of success. The Objective Structured Assessment of Technical Skill (OSATS) is a reliable and valid tool that has been increasingly used in orthopaedic skills training. It uses a global rating approach to structure expert evaluation of technical skills with the experts working from a list of operative competencies that are each rated on a 5-point Likert scale anchored by behavioral descriptors. Given the observational nature of its scoring, the OSATS might not effectively assess the quality of surgical results. QUESTIONS/PURPOSES: (1) Does OSATS scoring in an intraarticular fracture reduction training exercise correlate with the quality of the reduction? (2) Does OSATS scoring in a cadaveric extraarticular fracture fixation exercise correlate with the mechanical integrity of the fixation? METHODS: Orthopaedic residents at the University of Iowa (six postgraduate year [PGY]-1s) and at the University of Minnesota (seven PGY-1s and eight PGY-2s) undertook a skills training exercise that involved reducing a simulated intraarticular fracture under fluoroscopic guidance. Iowa residents participated three times during 1 month, and Minnesota residents participated twice with 1 month between their two sessions. A fellowship-trained orthopaedic traumatologist rated each performance using a modified OSATS scoring scheme. The quality of the articular reduction obtained was then directly measured. Regression analysis was performed between OSATS scores and two metrics of articular reduction quality: articular surface deviation and estimated contact stress. Another skills training exercise involved fixing a simulated distal radius fracture in a cadaveric specimen. Thirty residents, distributed across four PGY classes (PGY-2 and PGY-3, n = 8 each; PGY-4 and PGY-5, n = 7 each), simultaneously completed the exercise at individual stations. One of three faculty hand surgeons independently scored each performance using a validated OSATS scoring system. The mechanical integrity of each fixation construct was then assessed in a materials testing machine. Regression analysis was performed between OSATS scores and two metrics of fixation integrity: stiffness and failure load. RESULTS: In the intraarticular fracture model, OSATS scores did not correlate with articular reduction quality (maximum surface deviations: R = 0.17, p = 0.25; maximum contact stress: R = 0.22, p = 0.13). Similarly in the cadaveric extraarticular fracture model, OSATS scores did not correlate with the integrity of the mechanical fixation (stiffness: R = 0.10, p = 0.60; failure load: R = 0.30, p = 0.10). CONCLUSIONS: OSATS scoring methods do not effectively assess the quality of the surgical result. Efforts must be made to incorporate assessment metrics that reflect the quality of the surgical result. CLINICAL RELEVANCE: New objective, reliable, and clinically relevant measures of the quality of the surgical result obtained by a trainee are urgently needed. For intraarticular fracture reduction and extraarticular fracture fixation, direct physical measurement of reduction quality and of mechanical integrity of fixation, respectively, meet this need.

On orthopedic surgical skill prediction--the limited value of traditional testing.

OBJECTIVES: Primary: to assess the utility of our distal radius fracture repair model as a tool for examining residents' surgical skills. Secondary: to compare the residents' ability to achieve specific biomechanically measured fracture stability with traditional test scores. DESIGN: Our laboratory pioneered a model that measures biomechanical qualities of a repaired distal radius fracture. Before participation, all residents to be tested completed specified knowledge examinations. During the laboratory exercise, proctors observed each resident and completed Objective Structured Assessment of Technical Skills forms. At the completion of the laboratory, each specimen was tested biomechanically. Written examinations were completed in a proctored setting and computer examinations at home following the honor system. The laboratory exercise had adequate space and materials and allowed 60 minutes to complete the procedure. Residents had equal access to x-ray imaging. SETTING: The examination environment of the study resembled an operating room. PARTICIPANTS: Postgraduate years 3 and 4 orthopedic residents in our program were asked to participate. The institutional review board reviewed and approved the study as exempt. RESULTS: Fracture repair constructs capable of resisting loads expected during rehabilitation were created by approximately half the residents tested. However, traditional written and computer-based testing methods failed to predict which resident's fracture construct would pass the biomechanical testing. Prior in vivo similar case experience was not predictive. CONCLUSIONS: The idea that "book smart does not equal street smart" applies to the tested model. To measure surgical skill acquisition and increase public safety related to surgery, it will be necessary to employ new and specific examination methods that identify the skill to be acquired and test the acquisition of this skill as precisely as possible.

Biomechanical Test of Three Methods to Treat Thumb CMC Arthritis.

Background Basilar thumb arthritis, or first carpometacarpal arthritis, is a common condition, predominantly affecting women. Surgical treatment of this condition is highly varied. One common method consists of trapezium excision and a concomitant procedure for treatment of the "floating" thumb metacarpal. That procedures vary suggests that no method has an "outcome" advantage over another. However, the frequency of side effects is higher in more complex procedures. Question/Purposes We speculated that in vitro testing might identify a potential outcome difference that has been difficult to measure in vivo. Since the more complex procedure to treat this condition has a higher frequency of clinical side effects, we hoped to determine its functional value compared with less complex procedures. Methods A two-degrees-of-freedom biomechanical cadaver study examined simulated pinch strength and metacarpal subsidence during pinch. Three methods were compared with each other and against the normal pretreatment state: trapezial excision alone; trapezial excision and suture suspensionplasty (TESS); and trapezial excision followed by a ligament reconstruction using one-half of the flexor carpi radialis and tendon interposition (LRTI). Results After TESS, the loaded mean height of the arthroplasty space was 1.20 cm. This was statistically less than the pretreatment height of 1.50 cm (P < 0.05). However, the height maintained after LRTI (1.00 cm) was also statistically less than pretreatment state (P < 0.05) and less than TESS (P < 0.05). Trapezial excision alone was least successful at maintaining height. In contrast, the mean key pinch measured after treatment could not be predicted by treatment employed. Conclusions In summary, the tested technique of TESS appears to be biomechanically sound as related to maintenance of first metacarpal height. In in vitro testing it is superior to excision alone and at least equal to the ligament reconstruction method tested. Analysis of our data shows that 96% of the overall height (distance) maintained post excision is explained by surgical state. Clinical Relevance Trapezial height is preserved using support schemes in a laboratory setting. In the in vivo postsurgical state, clinical intrinsic muscle function may be superior when support is used compared with trapeziectomy alone.

Scapholunate interosseous ligament injuries: a retrospective review of treatment and outcomes in 82 wrists.

PURPOSE: To compare outcomes of treatment for scapholunate instability between acute (< 6 wk from injury) and chronic (> 6 wk) injuries, between complete and partial tears, and among surgical techniques; identify risk factors for surgical failure; and compare ligament reconstruction with repair with or without capsulodesis in the chronic period. METHODS: We performed a retrospective chart review of 82 primary scapholunate interosseous ligament surgeries, with median follow-up of 150 days. A total of 27 patients underwent surgery in the acute period and 50 in the chronic period. (In 5 patients we were unable to determine acuity or chronicity of injury.) In the chronic period, 16 patients underwent repair with or without capsulodesis, 27 underwent ligament reconstruction, and 7 underwent other procedures. RESULTS: Surgical intervention in the acute setting involved more complex injuries, most commonly used direct repair, and produced a significantly lower failure rate than chronic intervention. In the chronic setting, the most common technique was ligament reconstruction, which produced superior radiographic outcomes compared with repair with or without capsulodesis. Isolated scapholunate interosseous ligament injuries undergoing chronic surgical intervention composed the majority of failures. Workers' compensation status and chronic intervention were significant risk factors for failure. CONCLUSIONS: For chronic injuries, ligament reconstruction produced better radiographic outcomes than repair with or without capsulodesis. Acute intervention (within 6 wk) was preferable to chronic intervention for scapholunate interosseous ligament injuries, and a substantial number of isolated injuries failed to receive treatment in the acute period. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.

Simulation of altered excursion of the pronator quadratus.

Background Loss of forearm rotation is frequently seen after healing of distal radius fractures. Questions/Purposes Our purpose was to determine whether restricted excursion of the pronator quadratus muscle can affect forearm rotation. Methods We evaluated the relationship between pronator quadratus excursion and forearm rotation in a cadaveric model. Eight adult fresh-frozen above-elbow specimens were attached to a mounting device that permitted free rotation of the forearm around its ulnar axis. Forearm rotation was measured with a protractor while alternating pronation and supination loads were applied. Measurements were repeated after restricting the excursion of pronator quadratus by 10, 20, and 30% of its initial length. Results There was a mean 15° loss of supination for each 10% reduction in pronator excursion. There was no significant effect on pronation. Conclusions We conclude that, independent of any bone deformity or nearby joint stiffness, posttraumatic scarring of this muscle may result in a loss of supination.

Trapezium excision and suture suspensionplasty (TESS) for the treatment of thumb carpometacarpal arthritis.

Basilar thumb arthritis, or first carpometacarpal arthritis, is a common condition affecting older women and some men. It is estimated that as many as one third of postmenopausal woman are affected. Surgical treatment of this condition includes options ranging from arthrodesis to prosthetic arthroplasty. Intermediate options include complete or partial trapezial excision with or without interposition of a cushioning/stabilizing material (auto source, allo source, synthetic source). A multitude of methods appear to offer similar end results, although some methods definitely involve more surgical work and perhaps greater patient risk. Through retrospective evaluation of a cohort of patients who underwent suture suspensionplasty, we determined the postoperative effect on strength, motion, patient satisfaction, complications, and radiographic maintenance of the scaphoid-metacarpal distance. This review shows the method to be clinically effective and, by comparison with a more traditional ligament reconstruction trapezial interposition arthroplasty, the method does not require use of autograft or allograft tendon and has fewer surgical steps. Forty-four patients were included in this retrospective study. The results showed that 91% of patients were satisfied with the procedure. Pinch and grip strength remained the same preoperatively and postoperatively. A Disabilities of the Arm, Shoulder, and Hand patient-reported outcome instrument (DASH) scores averaged 30 at final follow-up. Three patients developed a late complication requiring further surgical intervention. In summary, this technique appears to be technically reproducible, requires no additional tendon material, and achieves objectively and subjectively similar results to other reported procedures used to manage first CMC Arthritis.

Percutaneous release of the A1 pulley: a cadaver study.

PURPOSE: Percutaneous release of the A1 pulley has been used for treatment of trigger fingers with success. However, lack of direct visualization raises concerns about the completeness of the release and about potential injury to the tendons or neurovascular structures. The purpose of this study was to assess the efficacy and safety of percutaneous release of the A1 pulley in a cadaveric model using a commonly available instrument, a #15 scalpel blade. METHODS: Fourteen fresh frozen cadaveric hands (54 fingers, thumbs excluded) were used. Landmarks were established for the A1 pulley based upon cutaneous features. Percutaneous release was performed using a #15 blade. The specimens were then dissected and examined for any tendon or neurovascular injury, and completeness of A1 pulley release was evaluated. RESULTS: There were 39 (72%) complete releases of the A1 pulley with 14 partial and 1 missed (failed) release. There was a 22% incidence of release of the proximal edge of the A2 pulley. However, there was no case of release of more than 25% of the A2 pulley length, nor was bowstringing of flexor tendons seen in these specimens. Eleven digits showed longitudinal scoring of the flexor tendons and 3 had partial tendon lacerations. No neurovascular injuries were noted. CONCLUSIONS: Percutaneous release of the A1 pulley using a #15 blade was associated with good efficacy and an acceptable margin of safety in this series. CLINICAL RELEVANCE: Percutaneous release of trigger digits may assume a greater role in the treatment of patients with trigger finger because of cost containment pressures. The data from this study suggest that the technique used in this study is both safe and effective. With use of proper anatomical guidelines, risk to neurovascular structures is low, although longitudinal scoring of the tendon can occur.

Treatment of distal radius fractures.

The clinical practice guideline is based on a systematic review of published studies on the treatment of distal radius fractures in adults. None of the 29 recommendations made by the work group was graded as strong; most are graded as inconclusive or consensus; seven are graded as weak. The remaining five moderate-strength recommendations include surgical fixation, rather than cast fixation, for fractures with postreduction radial shortening >3 mm, dorsal tilt >10 degrees , or intra-articular displacement or step-off >2 mm; use of rigid immobilization rather than removable splints for nonsurgical treatment; making a postreduction true lateral radiograph of the carpus to assess dorsal radial ulnar joint alignment; beginning early wrist motion following stable fixation; and recommending adjuvant treatment with vitamin C to prevent disproportionate pain.

Idiopathic osteonecrosis of the scaphoid: a series of 3 surgical cases.

Osteonecrosis of the scaphoid is usually a posttraumatic condition, but idiopathic cases are well known to occur. Magnetic resonance imaging is useful in distinguishing the types of osteonecrosis. In posttraumatic osteonecrosis, MRI abnormalities are in the proximal scaphoid that are consistent with interosseous vascular disruption, whereas in idiopathic osteonecrosis, the entire scaphoid is affected. The MRI findings correlate with histologic findings of osteonecrosis, and the etiology may be an extraosseous insult to the scaphoid blood supply. We presented a series of 3 cases of idiopathic global osteonecrosis of the scaphoid. All patients were found to have diffuse swelling of the dorsal wrist and probable effusion, and all had slow clinical deterioration. All 3 patients had surgical procedures that included bone grafting or intracarpal arthrodesis. At 5- to 10-year follow-up, all were satisfied with their treatment.