Do current upper limb orthotic classification systems help clinicians choose and design effective orthoses? A scoping review with expert interviews.

BACKGROUND: Orthosis (orthotic) fabrication is an essential part of the treatment plan for many upper extremity conditions. PURPOSE: We aim to comprehensively identify the current body of evidence about the purpose, structure, scope, and application of available orthotic classification systems. Our secondary aim was to know if the current classification systems can be used as a decision guide for clinicians. STUDY DESIGN: A scoping review. METHODS: A scoping review of research studies identified through data-based and gray literature was conducted to determine studies that addressed classification systems of the orthosis (orthotic) in the hand and upper limb. Two investigators screened study titles and abstracts and did the data extraction. To do a comprehensive review, all the hand therapy associations were contacted and asked to share their specific orthosis classification system. To answer our second aim, we discussed our findings with the experts in a panel. RESULTS: Twelve different classification systems were identified, which were developed with different aims. Five classification systems classified orthosis based on their function (n = 5, 50%); one based on therapeutic goals and proposed a decision algorithm. Two of the proposed systems were aimed at helping in decision-making or offering an algorithm for therapists to help them choose the proper orthosis. The expert panel process identified that the current classification systems could not help clinicians select proper orthosis for their patients. CONCLUSIONS: There are different classification systems which were developed with various aims. However, none of those can help clinicians make informed decisions about appropriate orthosis choices for their patients.

The Effect of Flexor Digitorum Profundus Repair Position Relative to Camper Chiasm on Tendon Biomechanics.

PURPOSE: The purpose of this study was to investigate the impact of repairing a zone II flexor digitorum profundus (FDP) laceration anatomically versus extra-anatomically on tendon loads and work of flexion (WOF). METHODS: Twenty digits from 5 cadaveric specimens were tested using an in vitro active finger motion simulator under 2 FDP tendon repair conditions: anatomic and extra-anatomic. Tensile loads in FDP and flexor digitorum superficialis (FDS), WOF, and total active finger range of motion (ROM) were measured using in-line load cells and electromagnetic tracking, respectively. RESULTS: The anatomic repairs had no effect on tendon loads or WOF for either FDP or FDS. The extra-anatomic repairs increased FDP loads by 32% and decreased FDS loads by 9% compared with those in the intact condition. This pattern was similar for WOF following extra-anatomic repairs, which increased FDP WOF by 31% and decreased FDS WOF by 18%. Comparing the 2 repairs, FDP loads and WOF were 25% and 22% greater, respectively, with extra-anatomic repairs compared with anatomic repairs, with no significant change in FDS. Total active ROM was not affected by either repair. CONCLUSIONS: In this in vitro cadaveric model, extra-anatomic repairs of FDP increased tendon loads and WOF compared with anatomic repairs. CLINICAL RELEVANCE: On the basis of this study, reconstitution of the anatomic relationship of FDP and FDS at the Camper chiasm during the repair of zone II flexor tendon lacerations is recommended.

Interfascicular Anatomy of the Motor Branch of the Ulnar Nerve: A Cadaveric Study.

PURPOSE: The motor branch of the ulnar nerve contains fascicles that innervate the intrinsic musculature of the hand. This cadaveric study aimed to describe the organization and consistency of the internal topography of the motor branch of the ulnar nerve. METHODS: Five fresh-frozen cadaveric specimens with an average age of 74 years (range, 65-88 years) were dissected. The ulnar nerve was exposed and transfixed to the underlying tissues to maintain its orientation throughout the dissection. The dorsal cutaneous branch (DCB) and the volar sensory branch were identified and reflected to expose the motor branch. The fascicles to the first dorsal interosseus (FDI), flexor pollicis brevis, and abductor digiti minimi (ADM) were identified. Internal neurolysis was performed distal to proximal to identify the interfascicular arrangement of these fascicles within the motor branch. The organization of these fascicles was noted, and the branch points of the DCB, FDI, and ADM were measured relative to the pisiform using a handheld electronic caliper. RESULTS: The internal topography of the motor branch was consistent among all specimens. Proximal to the pisiform, the arrangement from radial to ulnar was as follows: volar sensory branch, flexor pollicis brevis, FDI/intrinsic muscles, ADM, and DCB. The position of these branches remained consistent as the deep motor branch curved radially within the palm and traveled to the terminal musculature. The locations of the average branch points of the FDI, ADM, and DCB with respect to the pisiform were as follows: FDI, 4.6 cm distal (range, 4.1-4.9 cm), 4.5 cm radial (range, 4.1-4.9 cm); ADM, 0.65 cm distal (range, 0.3-1.1 cm), 0.7 cm radial (range, 0.3-1.1 cm), DCB, 7.7 cm proximal (range, 4.2-10.1 cm), and 0.4 cm ulnar (range, 0.3-0.8 cm). CONCLUSIONS: The internal topography of the ulnar nerve motor branch was consistent among the specimens studied. The topography of the motor branches was maintained as the motor branch turns radially within the palm. CLINICAL RELEVANCE: This study provides further understanding of the internal topography of the ulnar nerve motor branch at the wrist level.

Strength Comparison of Fibrin Glue and Suture Constructs in Upper Extremity Peripheral Nerve Coaptations: An In Vitro Study.

PURPOSE: To compare in vitro failure loads of nerve coaptations using fibrin glue alone, a suture alone, and a combination of fibrin glue and a suture. METHODS: The median, radial, and ulnar nerves of 15 fresh-frozen cadaveric upper extremity specimens (45 nerves in total) were dissected in vitro and transected 5 cm proximal to the wrist crease to simulate an injury requiring coaptation. Three coaptation techniques were used: fibrin glue alone, a suture alone, and a suture augmented with fibrin glue. The load to failure of each repair was measured using a linear servo-actuator with an in-line force sensor. The results were analyzed using 2-way repeated measures analysis of variance tests and pairwise comparisons with Bonferroni correction. RESULTS: Both the nerve coaptation technique and the specific nerve that was repaired had a significant effect on failure load. Suture-glue repair had the highest load to failure, 11.2 ± 2.9 N, and significantly increased the load to failure by 2.9 ± 1.7 N compared with glue repair alone. There was no significant difference between suture-glue repair and suture repair alone or between glue repair alone and suture repair alone. CONCLUSIONS: In this in vitro cadaveric model, nerve injury coaptation using both a suture and fibrin glue resulted in the strongest repair. The addition of fibrin glue may provide some benefit when used to augment suture repair, but when used in isolation, it is inferior to combined suture-and-glue constructs. CLINICAL RELEVANCE: Combined suture-and-glue nerve coaptations might be useful in the early postoperative period in increasing nerve repair strength and potentially reducing rupture rates.

Robot-Assisted Nasal Reconstruction: A Cadaveric Study.

OBJECTIVE: Manual contouring of cartilage for nasal reconstruction is tedious and time-consuming. The use of a robot could improve the speed and precision of the contouring process. This cadaveric study evaluates the efficiency and accuracy of a robot methodology for contouring the lower lateral cartilage of the nasal tip. METHODS: An augmented robot with a spherical burring tool attached was utilized to carve 11 cadaveric rib cartilage specimens. In phase 1, the right lower lateral cartilage was harvested from a cadaveric specimen and used to define a carving path for each rib specimen. In phase 2, the cartilage remained in situ during the scanning and 3-dimensional modeling. The final carved specimens were compared with the preoperative plans through topographical accuracy analysis. The contouring times of the specimens were compared with 14 retrospectively reviewed cases (2017-2020) by an experienced surgeon. RESULTS: Phase 1 root mean square error of 0.40±0.15 mm and mean absolute deviation of 0.33±0.13 mm. Phase 2 root mean square error of 0.43 mm and mean absolute deviation of 0.28 mm. The average carving time for the robot specimens was 14±3 minutes and 16 minutes for Phase 1 and Phase 2, respectively. The average manual carving by an experienced surgeon was 22±4 minutes. CONCLUSIONS: Robot-assisted nasal reconstruction is very precise and more efficient than manual contouring. This technique represents an exciting and innovative alternative for complex nasal reconstruction.

A description of the barriers, facilitators, and experiences of hand therapists in providing remote (tele) rehabilitation: An interpretive description approach.

BACKGROUND: Telerehabilitation is increasingly being used to meet the rehabilitation needs of situations where face-to-face therapy is not possible. Nevertheless, reports on barriers and facilitators of implementing this method from the perspective of therapists still need to be made available. PURPOSE: To investigate the experiences of hand therapists when implementing telerehabilitation, examining the difficulties, barriers, and facilitators encountered during its implementation. STUDY DESIGN: Qualitative study. METHODS: This study used a purposive sampling method to recruit therapists with varying experiences in telerehabilitation and conducted semi-structured interviews. Data collection and analysis continued iteratively until thematic saturation was achieved. A total of 14 therapists were interviewed via Zoom. The interviews were recorded, transcribed, and qualitatively analyzed using thematic analysis. The process of interpretive description guided interviews and analysis of the interviews to identify key barriers and facilitators in providing telerehabilitation. RESULTS/DISCUSSION: Six main themes and 10 corresponding sub-themes were constructed concerning facilitators and barriers to telerehabilitation: factors related to the patient, therapy, therapists, injury, technology, and policy. Therapists implemented different coping strategies in their interventions and measurements to facilitate treatment. However, some interventions, such as orthotic fabrication, could not be done online. Educating therapists, providing a standard method, and integrating with in-person rehabilitation can overcome the barriers to telerehabilitation in hand therapy. CONCLUSIONS: Technology was the main facilitator and, on the other hand, a barrier to providing online hand therapy interventions. Therapists generally reported high satisfaction and usability of this method. Despite all barriers, telerehabilitation can be implemented as a part of hand therapy interventions alongside face-to-face therapy as a hybrid method. The barriers and facilitators experienced and raised by therapists can be added to what is already known regarding telerehabilitation in hand therapy. They might be applied to guide therapeutic procedures and upcoming studies.

The Evaluation of a Flexor Digitorum Profundus-to-Volar Plate Zone I Repair Versus Button Repair: An In vitro Biomechanics Study.

PURPOSE: The purpose of the study was to evaluate joint kinematics and tendon work of flexion (WOF) following a flexor digitorum profundus (FDP)-to-volar plate (VP) repair technique relative to a pullout button for zone I flexor tendon injuries. METHODS: Fourteen digits were tested using an in vitro active finger motion simulator under 3 repaired conditions following a simulated zone I avulsion: button, FDP-VP, and "no slack" FDP-VP (corrected for additional VP length). Outcome metrics included active joint range of motion (ROM), fingertip strength, FDP and flexor digitorum superficialis tensile loads, and WOF. RESULTS: The button and FDP-VP techniques restored WOF to the intact condition for FDP and flexor digitorum superficialis. All repairs restored distal interphalangeal joint ROM and kinematics to the intact condition. Similarly, all repairs restored WOF; however, the "no slack" FDP-VP significantly increased WOF by 10% to 12% over the simple FDP-VP repair. The button technique had similar fingertip strength to the intact condition, whereas the FDP-VP repairs significantly reduced peak fingertip strength from intact, albeit only 1-2 N compared with the button repair. CONCLUSION: In this in vitro cadaveric model, the button and FDP-VP techniques restored WOF and ROM to within intact levels, with no difference between these repairs in all measured outcome metrics. CLINICAL RELEVANCE: Based on its initial strength and its equal biomechanical performance compared with the button repair, the FDP-VP technique may be a viable option for treating FDP avulsions.

Morphology of Proximal Ulna Bare Area: A Guide for Olecranon Osteotomy.

PURPOSE: Olecranon osteotomy is commonly used to obtain access to the distal humerus for fracture fixation. The goal of this study was to accurately describe the anatomy of the bare area to minimize articular cartilage damage while performing olecranon osteotomies. METHODS: Twenty cadaveric ulnae were denuded to expose the bare area. Laser surface mapping was used to create 3-dimensional models, and the nonarticular portions of the ulnae were digitally measured. RESULTS: The morphology of the bare area from all aspects of the proximal ulna was defined. The central bare area was consistent in its location, 4.9 ± 1.5 mm distal to the deepest portion of the trochlear notch and 23.2 ± 2.3 mm distal to the olecranon tip. The maximum chevron osteotomy apical angle to stay within the bare area averaged 110° ± 11.8°. However, there was little tolerance for error without the risk of violating the articular cartilage. With transverse osteotomy, averaging 18° ± 10.6° in the coronal plane, there is less risk of damaging the articular cartilage. CONCLUSIONS: Transverse osteotomy perpendicular to the posterior surface of the ulna aiming at the visible bare area on the medial and lateral sides of the greater sigmoid notch may reduce the chances of violating the nonvisible articular cartilage of the proximal ulna. Based on the findings of this study, if chevron osteotomy is used, a shallow apex distal angle of more than 110° is recommended. CLINICAL RELEVANCE: This study provides intraoperative landmarks to guide surgeons performing olecranon osteotomies to stay within the bare area.

Does the osteoarthritic shoulder have altered rotator cuff vectors with increasing glenoid deformity? An in silico analysis.

BACKGROUND: A transverse force couple (TFC) functional imbalance has been demonstrated in osteoarthritic shoulders by recent 3-dimensional (3D) muscle volumetric studies. Altered rotator cuff vectors may be an additional factor contributing to a muscle imbalance and the propagation of glenoid deformity. METHODS: Computed tomography images of 33 Walch type A and 60 Walch type B shoulders were evaluated. The 3D volumes of the entire subscapularis, supraspinatus, and infraspinatus-teres minor (ISP-Tm) and scapula were manually segmented. The volume masks and scapular landmarks were imported into MATLAB to create a coordinate system, enabling calculation of muscle force vectors. The direction of each muscle force vector was described in the transverse and vertical plane, calculated with respect to the glenoid. Each muscle vector was then resolved into compression and shear force across the glenoid face. The relationship between muscle force vectors, glenoid retroversion or inclination, compression/shear forces on the glenoid, and Walch type was determined using linear regression. RESULTS: In the transverse plane with all rotator cuff muscles combined, increasing retroversion was significantly associated with increasing posterior drag (P < .001). Type B glenoids had significantly more posterior drag than type A (P < .001). In the vertical plane for each individual muscle group and in combination, superior drag increases as superior inclination increases (P < .001). Analysis of individual muscle groups showed that the anterior thrust of ISP-Tm and supraspinatus switched to a posterior drag at 8° and 10° of retroversion respectively. The compression force on the glenoid face by ISP-Tm and supraspinatus did not change with increasing retroversion for type A shoulders (P = .592 and P = .715, respectively), but they did for type B shoulders (P < .001 for both). The glenoid shear force ratio in the transverse plane for the ISP-Tm and supraspinatus moved from anterior to posterior shear with increasing glenoid retroversion, crossing zero at 8° and 10° of retroversion, whereas the subscapularis exerted a posterior shear force for every retroversion angle. CONCLUSION: Increased glenoid retroversion is associated with increased posterior shear and decreased compression forces on the glenoid face, explaining some of the pathognomonic bone morphometrics that characterize the osteoarthritic shoulder. Although the subscapularis always maintains a posterior thrust, the ISP-Tm and supraspinatus together showed an inflection at 8° and 10° of retroversion, changing from an anterior thrust to a posterior drag. This finding highlights the importance that in anatomic TSA the rotator cuff functional balance might be better restored by correcting glenoid retroversion to less than 8°.

Use of Thermoplastic Rings Following Venting of Flexor Tendon Pulleys: A Biomechanical Analysis.

PURPOSE: Normal digital flexion relies on flexor tendon pulleys to convert linear muscular force to angular digital motion. However, there is a growing trend to vent them partially during flexor tendon repair. The objective of this study was to examine the effects of a thermoplastic ring, acting as an external pulley, on flexor tendon biomechanics and finger range of motion (ROM) after pulley venting. METHODS: We tested 15 cadaveric digits using an in vitro active finger motion simulator. We measured loads induced by flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) as well as joint ROM with sequential sectioning of the A2, A3, and A4 pulleys compared with an intact pulley condition. At each stage, external thermoplastic pulley rings were applied snugly over the proximal and middle phalanges to recreate A2 and A4 function, respectively. RESULTS: After complete venting of the A2, A3, and A4 pulleys, proximal interphalangeal joint ROM significantly decreased by 13.4° ± 2.7° and distal interphalangeal joint ROM decreased by 15.8° ± 2.1°. Application of external rings over the proximal and middle phalanx resulted in a residual ROM decrease of 8.3° ± 1.9° at the proximal interphalangeal joint and 7.9° ± 2.1° at the distal interphalangeal joint, nearly restoring ROM. Similarly, complete pulley venting resulted in reduced FDS load by 37% and FDP load by 50% compared with intact pulleys. After application of external rings, loads were restored almost to normal, with a 9% reduction for FDS load and 9% reduction for FDP load compared with intact pulleys. CONCLUSIONS: The application of thermoplastic rings acting as external pulleys is an effective, noninvasive, and reproducible approach to restore flexor tendon biomechanics and digit ROM after pulley venting. CLINICAL RELEVANCE: Thermoplastic rings may be a useful therapeutic adjunct in restoring joint ROM and flexor tendon loads after surgical venting of the pulleys.

Does the Walch type B shoulder have a transverse force couple imbalance? A volumetric analysis of segmented rotator cuff muscles in osteoarthritic shoulders.

BACKGROUND: The etiology of the Walch type B shoulder remains unclear. We hypothesized that a scapulohumeral muscle imbalance, due to a disturbed transverse force couple (TFC) between the anterior and posterior rotator cuff muscles, may have a role in the pathogenesis of the type B morphology. The purpose of this study was to determine whether there is a TFC imbalance in the Walch type B shoulder using an imaging-based 3-dimensional (3D) volumetric and fatty infiltration assessment of segmented rotator cuff muscles. METHODS: Computed tomography images of 33 Walch type A and 60 Walch type B shoulders with the complete scapula and humerus including the distal humeral epicondyles were evaluated. The 3D volumes of the entire subscapularis, supraspinatus, and infraspinatus-teres minor (Infra-Tm) were manually segmented and analyzed. Additionally, anthropometric parameters including glenoid version, glenoid inclination, posterior humeral head subluxation, and humeral torsion were measured. The 3D muscle analysis was then compared with the anthropometric parameters using the Wilcoxon rank sum and Kruskal-Wallis tests. RESULTS: There were no significant differences (P > .200) in muscle volume ratios between the Infra-Tm and the subscapularis in Walch type A (0.93) and type B (0.96) shoulders. The fatty infiltration percentage ratio, however, was significantly greater in type B shoulders (0.94 vs. 0.75, P < .001). The Infra-Tm to subscapularis fatty infiltration percentage ratio was significantly larger in patients with >75% humeral head subluxation than in those with 60%-75% head subluxation (0.97 vs. 0.74, P < .001) and significantly larger in patients with >25° of retroversion than in those with <15° of retroversion (1.10 vs. 0.75, P = .004). The supraspinatus fatty infiltration percentage was significantly lower in Walch type B shoulders than type A shoulders (P = .004). Walch type A shoulders had mean humeral retrotorsion of 22° ± 10° whereas Walch type B shoulders had humeral retrotorsion of only 14° ± 9° relative to the epicondylar axis (P < .001). CONCLUSION: The TFC is in balance in the Walch type B shoulder in terms of 3D volumetric rotator cuff muscle analysis; however, the posterior rotator cuff does demonstrate increased fatty infiltration. Posterior humeral head subluxation and glenoid retroversion, which are pathognomonic of the Walch type B shoulder, may lead to a disturbance in the length-tension relationship of the posterior rotator cuff, causing fatty infiltration.

Biomechanical Impact of a Zygoma Complex Fracture Using Human Cadaver.

ABSTRACT: Zygomaticomaxillary complex fractures are common in midface trauma, with treatment often involving repair using titanium mini plates. However, the need for plate fixation along the zygomaticomaxillary suture on the infraorbital rim remains controversial. This study utilized a previously reported bite force simulator to investigate craniofacial strain patterns following zygomaticomaxillary complex fracture repairs with and without plating of the infraorbital rim. Osteotomies were made to 6 fresh-frozen cadaveric heads to simulate 2 types of zygomatic complex fractures: a dipod fracture with osteotomies at the zygomaticofrontal and zygomaticomaxillary sutures, and a tripod fracture with an additional osteotomies at the zygomaticotemporal suture. Repairs with and without the use of a titanium mini plate across the infraorbital rim were compared in both dipod and tripod fractures. Physiologically proportional masticatory loads were applied using the bite force simulator by actuating intrinsic muscle lines of action. The outcome metric was facial bone strains measured using uniaxial strain gauges. Mixed-effects linear models did not find a significant main effect on the overall strain pattern with the use of an infraorbital rim plate in both dipod (P = 0.198) and tripod (P = 0.117) fracture repairs. However, statistically significant differences were found locally at the zygomatic buttress (P = 0.019) and the zygomatic arch (P = 0.027) on the fractured side in dipod fractures. This is the first known study that successfully utilized a mechanical simulator to reproduce physiological intrinsic masticatory loads in a fracture fixation study. This new technology opens avenues for future biomechanical investigations on maxillofacial fracture repairs and other surgical treatments.

Evaluation of the content validity index of the Australian/Canadian osteoarthritis hand index, the patient-rated wrist/hand evaluation and the thumb disability exam in people with hand arthritis.

BACKGROUND: The Australian/Canadian Osteoarthritis Hand Index (AUSCAN), the Patient-Rated Wrist/Hand Evaluation (PRWHE) and the Thumb Disability Exam (TDX) are patient-reported outcome measures (PROM) designed to assess pain and hand function in patients with hand arthritis, hand pain and disability, or thumb pathology respectively. This study evaluated the content validity of AUSCAN, PRWHE and TDX in people with hand arthritis. METHODS: This study enrolled participants with hand arthritis to rate the items of all 3 PROM in terms of relevance and clarity. The Content Validity Index (CVI) was computed for each item in each scale (I-CVI) as well as for the overall scale (S-CVI). Kappa was used to determine the inter-rater agreement among the raters. RESULTS: Overall, 64 individuals with hand arthritis (27% with OA, 67% with rheumatoid arthritis and 6% with psoriatic arthritis) participated in the study. The I-CVI for all items and all scales were very high (I-CVI > 0.76) and the modified Kappa agreement among the raters demonstrated excellent agreement (k > 0.76). The S-CVI for all PROMs was very high for relevance (AUSCAN = 0.92, 95% CI 0.90 to 0.94; PRWHE = 0.85, 95% CI 0.82 to 0.88 and TDX = 0.87, 95% CI 0.85 to 0.89) and for clarity (AUSCAN = 0.99, 95% CI 0.98 to 1.00; PRWHE = 0.95, 95% CI 0.93 to 0.97 and TDX = 0.91, 95% CI 0.89 to 0.94), respectively. CONCLUSIONS: This study demonstrated very high content validity indices for the AUSCAN, PRWHE and TDX; with strong consensus across raters. This augments prior studies demonstrating appropriate statistical measurement properties, to provide confidence that all three measures assess important patient concepts of pain and disability.

Osteoarticular distal clavicle autograft for the management of instability-related glenoid bone loss: an anatomic and cadaveric study.

BACKGROUND: The reconstructive options for instability-related anterior glenoid bone loss include iliac crest autograft, allograft, or coracoid transfer. The use of distal clavicle autograft (DCG) has also been described. The purpose of this imaging and cadaveric study was to examine the dimensions, morphology, and bone density of the DCG and compare it with the Latarjet procedure. METHODS: We used 49 computed tomography scans from patients with anterior glenoid bone loss to measure the distal clavicle dimensions and bone density. Four glenoid reconstructions were simulated to compare techniques: DCG inferior surface toward glenoid (DCG inferior), DCG superior, classic Latarjet, and congruent-arc Latarjet. In addition, the morphology of the DCG was assessed on computed tomography and confirmed in 27 cadavers. RESULTS: The mean width of the DCG (11 mm) was significantly greater (P < .001) than that of the classic Latarjet orientation (9 mm) but less (P = .002) than that of the congruent-arc orientation (12 mm). The DCG had a lower bone density than the coracoid (P < .001). The mean articular surface area of the DCG-inferior orientation was 208 mm2, which was greater (P = .013) than that of the DCG-superior orientation (195 mm2) and not significantly different (P = .44) than that of the classic Latarjet orientation (214 mm2). The surface area of the congruent-arc orientation was greater (285 mm2, P < .001) than that of all other graft orientations. The DCG-inferior orientation was able to reconstruct 22% of the glenoid articular surface; DCG-superior orientation, 21%; classic Latarjet orientation, 23%; and congruent-arc orientation, 30%. Three DCG morphologies were identified: square (34%), trapezoidal (53%), and rounded (13%). CONCLUSIONS: The distal clavicle osteoarticular graft was able to reconstruct 22% of the glenoid face. Three morphologies of the distal clavicle were identified, with the square and trapezoidal morphologies most amenable for glenoid reconstruction.

Revision shoulder arthroplasty: a systematic review and comparison of North American vs. European outcomes and complications.

BACKGROUND: Joint registries provide invaluable data on primary arthroplasties with revision as the endpoint; however, the revision outcomes are often excluded. Therefore, a PROSPERO registered review (CRD42015032531) of all revision studies in North America and Europe was conducted to evaluate demographics, etiologies and indications, implant manufacturer, and complications by geographic region. METHODS: The MEDLINE, EMBASE, and CENTRAL databases were searched for revision arthroplasty clinical studies with a minimum mean 24-month follow-up. There were no language exclusions. Articles published in German, French, and Italian were reviewed by research personnel proficient in each language. RESULTS: The mean age at revision was 66 ± 5 years (male = 759, female = 1123). The male-female ratio in North American and Europeans studies was 43:57 and 34:66, respectively. The most common etiology for primary surgery in both regions was osteoarthritis or glenoid arthrosis (38%). The most common revision indication overall was rotator cuff tear, deficiency, or arthropathy (26%). The most common implant type used in revisions was a reverse shoulder arthroplasty (54%). The complication rate for all revisions was 17%. There were a total of 465 complications, and of those, 74% lead to a reoperation. CONCLUSION: Generally, shoulder arthroplasties are designed to last 10-15 years; however, revisions are being performed at a mean 3.9 years from the primary procedure, based on the published studies included in this systematic review. Additionally, of the complications, a large number (74%) went on to a reoperation. Further insight into the reasons for early revisions and standardized reporting metrics and data collection on revisions is needed.

Bite Force Simulator: A Novel Technique to Simulate Craniofacial Strain In Vitro.

Existing in vitro simulators rely on external manipulation of the skull to replicate masticatory forces; however, external manipulations do not accurately represent internal loads as in physiological muscle forces.The purpose of the project is to develop an in vitro simulator that internally replicates the forces of mastication. The simulator has 3-dimensional-printed piston mounts that are reverse-engineered using a computed tomography scan of the specimen. The mounts are attached to the skull at muscle attachment sites using adhesive. The pneumatic pistons are sutured to muscle tendons; when the pistons are activated, they pull on the tendons which proportionally replicate muscle loads. The force output of the pistons can be individually modified by a custom software. Strain gauges are attached to craniofacial bones to measure deformation under replicated muscle loads. A 6 degrees-of freedom force sensor is placed intraorally to measure the generated bite force.The methodology was validated on 6 fresh-frozen cadaveric heads. Change in strain measurements was observed with change in simulated muscle loads. The simulator can validate computer simulation models and provide an experimental platform for craniofacial and dental implants. It sets the framework for a new, more physiologically consistent way of studying craniofacial stresses.

Evaluation of individual finger forces during activities of daily living in healthy individuals and those with hand arthritis.

INTRODUCTION: Measuring finger forces during activities of daily living and how these forces change for individuals with pathologies such as arthritis is valuable to our understanding of hand function. PURPOSE OF THE STUDY: The purpose of this study was to determine the forces of individual fingers during the performance of daily activities in healthy participants and determine the envelope of these applied forces. METHODS: This is a cross-sectional study investigating twenty-five healthy participants (12 female: 22-65 years old and 13 male: 20-53 years old) and participants with osteoarthritis (12 female: 52-79 years old and 9 male: 64-79 years old) examined at one time point. The force sensors were calibrated for each individual using a load cell to provide force output in Newtons. Each participant performed 19 activities of daily living two times. Force was plotted over time for each task, and the maximum force in each finger during that task was evaluated. RESULTS: The range of applied forces was 1.4 ± 0.6 N to 34.8 ± 1.6 N for healthy participants and 2.3 ± 1.0 N to 30.7 ± 3.7 N for those with osteoarthritis. DISCUSSION: Sensors allowed for real-time monitoring of finger forces during tasks of daily life. This provides the opportunity to isolate hand grips based on finger recruitment and provide information about the magnitude of forces during the activity. CONCLUSION: Measurement of individual finger forces can provide more accurate biomechanical models of the hand and determine the effect of disease on hand functions.

The Walch type B humerus: glenoid retroversion is associated with torsional differences in the humerus.

BACKGROUND: The Walch type B glenoid has the hallmark features of retroversion, joint subluxation, and bony erosion. Although the type B glenoid has been well described, the morphology of the corresponding type B humerus is poorly understood. As such, the aim of this imaging-based anthropometric study was to investigate humeral torsion in Walch type B shoulders. METHODS: Three-dimensional models of the full-length humerus were generated from computed tomography data for the Walch type B group (n = 59) and for a control group of normal nonarthritic shoulders (n = 59). An anatomic humeral head-neck plane was created and used to determine humeral torsion relative to the epicondylar axis. Measurements were repeated, and intraclass correlation coefficients were calculated. RESULTS: The type B humeri had significantly (P < .001) less retrotorsion (14° ± 9°) than the control group (36° ± 12°) relative to the epicondylar axis. Male and female individuals within the control group showed statistically significant differences in humeral torsion (P = .043), which were not found in the type B group. Inter-rater reliability showed excellent agreement for humeral torsion (intraclass correlation coefficient, 0.962). A subgroup analysis between Walch type B2 and B3 shoulders showed no significant differences in any of the humeral or glenoid parameters. CONCLUSION: The Walch type B humerus has significantly less retrotorsion than non-osteoarthritic shoulders. At present, it is unknown whether the altered humeral retrotorsion is a cause or effect of the type B glenoid. In addition, it is unknown whether surgeons should be reconstructing type B2 humeral component version to pathologic torsion or to nonpathologic population means to optimize arthroplasty survivorship.

The effectiveness of joint-protection programs on pain, hand function, and grip strength levels in patients with hand arthritis: A systematic review and meta-analysis.

STUDY DESIGN: Systematic review with meta-analysis. INTRODUCTION: Joint protection (JP) has been developed as a self-management intervention to assist people with hand arthritis to improve occupational performance and minimize joint deterioration over time. PURPOSE OF THE STUDY: We examined the effectiveness between JP and usual care/control on pain, hand function, and grip strength levels for people with hand osteoarthritis and rheumatoid arthritis. METHODS: A search was performed in 5 databases from January 1990 to February 2017. Two independent assessors applied Cochrane's risk of bias tool, and a Grading of Recommendations Assessement, Development and Evaluation (GRADE) approach was adopted. RESULTS: For pain levels at short term, we found similar effects between JP and control standardized mean difference (SMD; -0.00, 95% confidence interval [CI]: -0.42 to 0.42, I2 = 49%), and at midterm and long-term follow-up, JP was favored over usual care SMD (-0.32, 95% CI: -0.53 to -0.11, I2 = 0) and SMD (-0.27, 95% CI: -0.41 to -0.12, I2 = 9%), respectively. For function levels at midterm and long-term follow-up, JP was favored over usual care SMD (-0.49, 95% CI: -0.75 to -0.22, I2 = 34%) and SMD (-0.31, 95% CI: -0.50 to -0.11, I2 = 56%), respectively. For grip strength levels, at long term, JP was inferior over usual care mean difference (0.93, 95% CI: -0.74 to 2.61, I2 = 0%). CONCLUSIONS: Evidence of very low to low quality indicates that the effects of JP programs compared with usual care/control on pain and hand function are too small to be clinically important at short-, intermediate-, and long-term follow-ups for people with hand arthritis.

Characterization of the Walch B3 glenoid in primary osteoarthritis.

BACKGROUND: The type B3 glenoid is an addition to the Walch classification. A potential etiologic theory is that it is a progression of the B2. It is characterized by uniconcavity, absent paleoglenoid, medialization, retroversion, and subluxation. The purpose of this study was to describe the morphology of B3 glenoids. METHODS: Fifty-two patients with B3 glenoids underwent 3-dimensional analysis of computed tomography data. Glenoid measurements (retroversion, inclination, medialization) and humeral head subluxation according to the scapular and glenoid planes were determined. The measured variables were compared between male and female patients. RESULTS: The mean B3 retroversion, inclination, and medialization were 24° ± 7°, 8° ± 6° superior, and 14 ± 4 mm, respectively. The mean posterior subluxation was 80% ± 8% and 54% ± 6% according to the scapular and glenoid planes, respectively. There were no differences in B3 characteristics between sexes (P > .05). A significant correlation existed between glenoid retroversion and humeral head subluxation relative to the scapular plane, with every 1° increase in retroversion translating to a 1% increase in subluxation (P < .001). In contrast, when referencing the glenoid plane, the humeral head remained concentric to the erosion. CONCLUSIONS: The B3 is uniconcave and retroverted. As glenoid retroversion increases, posterior humeral head subluxation significantly increases as referenced to the scapular plane; however, when referenced to the glenoid plane, the head remains concentric to the erosion. This appearance of "concentricity" is acquired secondary to the wear pattern, creating a uniconcave glenoid. Therefore, surgeons should be aware that the visualized concentricity is a product of the erosion pattern and thus may conceal a greater amount of subluxation potential.