A novel fragment specific classification of complex olecranon fractures: 3-dimensional model design, radiological validation, and proposed surgical algorithm

BACKGROUND

Current classifications for proximal ulna fracture patterns rely on qualitative data and cannot inform surgical planning. We propose a new classification system based on a biological and anatomical stress analysis. Our hypothesis is that fragment types in complex fractures can be predicted by the tendon and ligament attachments on the proximal ulna.

METHODS

First, we completed a literature review to identify quantitative data on proximal ulna soft tissue attachments. On this basis, we created a 3-dimensional model of ulnar anatomy with SliceOMatic and Catia V5R20 software and determined likely locations for fragments and fracture lines. The second part of the study was a retrospective radiological study. A level-1 trauma radiological database was used to identify computed tomography scans of multifragmentary olecranon fractures from 2009 to 2021. These were reviewed and classified according to the "fragment specific" classification and compared to the Mayo and the Schatzker classifications.

RESULTS

Twelve articles (134 elbows) met the inclusion criteria and 7 potential fracture fragments were identified. The radiological study included 67 preoperative computed tomography scans (mean 55 years). The fragments identified were the following: posterior (40%), intermediate (42%), tricipital (100%), supinator crest (25%), coronoid (18%), sublime tubercle (12%), and anteromedial facet (18%). Eighteen cases (27%) were classified as Schatzker D (comminutive) and 21 (31%) Mayo 2B (stable comminutive). Inter-rater correlation coefficient was 0.71 among 3 observers.

CONCLUSION

This proposed classification system is anatomically based and considers the deforming forces from ligaments and tendons. Having a more comprehensive understanding of complex proximal ulna fractures would lead to more accurate fracture evaluation and surgical planning.

Elucidation of the radius and ulna fracture mechanisms in toy poodle dogs using finite element analysis

Fractures occurring in the distal radius and ulna of toy breed dogs pose distinctive challenges for veterinary practitioners, requiring specialized treatment approaches primarily based on anatomical features. Finite Element Analysis (FEA) was applied to conduct numerical experiments to determine stress distribution across the bone. This methodology offers an alternative substitute for directly investigating these phenomena in living dog experiments, which could present ethical obstacles. A three-dimensional bone model of the metacarpal, carpal, radius, ulna, and humerus was reconstructed from Computed Tomography (CT) images of the toy poodle and dachshund forelimb. The model was designed to simulate the jumping and landing conditions from a vertical distance of 40 cm to the ground within a limited timeframe. The investigation revealed considerable variations in stress distribution patterns between the radius and ulna of toy poodles and dachshunds, indicating notably elevated stress levels in toy poodles compared to dachshunds. In static and dynamic stress analysis, toy poodles exhibit peak stress levels at the distal radius and ulna. The Von Mises stresses for toy poodles reach 90.07 MPa (static) and 1,090.75 MPa (dynamic) at the radius and 1,677.97 MPa (static) and 1,047.98 MPa (dynamic) at the ulna. Conversely, dachshunds demonstrate lower stress levels for 5.39 MPa (static) and 231.79 MPa (dynamic) at the radius and 390.56 MPa (static) and 513.28 MPa (dynamic) at the ulna. The findings offer valuable insights for modified treatment approaches in managing fractures in toy breed dogs, optimizing care and outcomes.

Consolidation rate in ulnar shortening osteotomy with the APTUS Wrist plate

INTRODUCTION

Ulnocarpal impaction syndrome causes pain on the ulnar side of the wrist. Various surgical techniques have been described. Ulnar shortening osteotomy is now a standard treatment. However, it is associated with complications such as non-union of the osteotomy site. The main study objective was to report the rate of radiographic consolidation after ulnar shortening osteotomy with a cutting guide.

MATERIAL AND METHODS

This multicenter retrospective study of 30 cases reported clinical and radiographic criteria at a minimum 6 month's follow-up.

RESULTS

The non-union rate was 3.4%. One case presented non-union of the osteotomy site. 87% of patients were satisfied or very satisfied with the procedure. Mean VAS pain rating was 2.7 ± 2.4. Mean QuickDASH and PRWE scores were 24.7 ± 19.2 and 28.6 ± 25.). Mean strength on Jamar dynamometer was 27.4 ± 8.9 kg. One patient developed complex regional pain syndrome. Five patients required plate removal for hardware-related discomfort.

DISCUSSION

Ulna shortening osteotomy with the Aptus Wrist plate provides a standardized approach to the surgical treatment of ulnocarpal impaction syndrome. Compared with other series in the literature, the procedure provided satisfactory consolidation and clinical results.

Unifocal Tubercular Osteomyelitis of Ulna Diaphysis in a Child: A Case Report

Introduction

Osteoarticular tuberculosis (OATB) contributes to around 10% of extrapulmonary tuberculosis of which the spine is the most common site. Isolated involvement of ulna diaphysis is extremely rare. We present a case of unifocal tuberculous osteomyelitis of ulna diaphysis in a 3 -year-old male child and highlight its resemblance with musculoskeletal tumors and stress the importance of GeneXpert mycobacterium tuberculosis (MTB)/resistance to rifampicin (RIF) in the diagnosis of OATB.

Case Report

A mother of a 2-year-old male child incidentally noticed that her son complained of left forearm pain. She was not sure of any fall or trauma to the forearm. No history of fever or other constitutional symptoms was present. Clinical examination was uneventful except for local tenderness in over the dorsomedial aspect of the left mid forearm. A plain radiograph revealed an oval solitary lytic lesion over distal one-third ulna diaphysis. A needle biopsy was done after clinical, hematological, and radiological evaluation, and finally, GeneXpert detected tuberculosis without RIF. No further tests were required and the child was started on antitubercular therapy (ATT) which resulted in complete healing without any symptoms.

Conclusion

The authors conclude that it is therefore essential to consider tuberculosis in the differential diagnosis while evaluating a lytic bone lesion. Where possible, all patients should have a biopsy of the lesion and provide a specimen for GeneXpert MTB/RIF to confirm the diagnosis and drug susceptibility testing.

Ulnar shape of extant primates: Functional signals and covariation with triquetrum shape

OBJECTIVES

In this study, we investigated the shape differences of the distal ulna in a phylogenetic context among a broad range of primate taxa. Furthermore, we evaluated covariation between ulnar and triquetrum shape and a possible association between ulnar shape and locomotor behavior.

MATERIALS AND METHODS

We applied 3D geometric morphometrics on a large dataset comprising the distal ulna of 124 anthropoid primate specimens belonging to 12 different genera. For each species, a mean shape was calculated using 11 Procrustes-aligned surface landmarks on the distal ulna. These mean shapes are used in a bgPCA, pPCA, and PACA and 3D morphs were used to visualize more subtle differences between taxa. A p2B-PLS analysis was performed to test the covariance between distal ulnar and triquetrum shape.

RESULTS

The results show that more closely related species exhibit a similar distal ulnar shape. Overall, extant hominid ulnae show a shape shift compared to those of extant monkeys and hylobatids. This includes a shortening of the ulnar styloid process and dorspalmarly widening of the ulnar head, shape characteristics that are independent of phylogeny. Within the hominids, Pongo pygmaeus seem to possess the most plesiomorphic distal ulnar shape, while Gorilla and Homo sapiens display the most derived distal ulna. Cercopithecoids, hylobatids, and P. pygmaeus are characterized by a relatively deep ECU groove, which is a shape trait dependent of phylogeny. Although there was no significant covariation between distal ulnar shape and triquetrum shape, the shape differences of the distal ulna between the different primate taxa reveal a possible link with locomotor behavior.

CONCLUSIONS

The comparative analyses of this study reveal different shape trends in a phylogenetic context. Highly arboreal primates, such as hylobatids and Ateles fusciceps, show a distal ulnar morphology that appears to be adapted to tensile and torsional forces. In primates that use their wrist under more compressive conditions, such as quadrupedal cercopithecoids and great apes, the distal ulnar morphology seems to reflect increased compressive forces. In modern humans, the distal ulnar shape can be associated to enhanced manipulative skills and power grips. There was no significant covariation between distal ulnar shape and triquetrum shape, probably due to the variation in the amount of contact between the triquetrum and ulna. In combination with future research on wrist mobility in diverse primate taxa, the results of this study will allow us to establish form-function relationships of the primate wrist and contribute towards an evidence-based interpretation of fossil remains.

Feline radial and ulnar diaphyseal fractures: a retrospective study of 49 cases comparing single bone fixation and dual bone fixation

OBJECTIVES

The objectives of this study were to report the complications in radial and ulnar diaphyseal fractures in cats and to compare the differences in outcome between single and dual bone internal fixation.

METHODS

Medical records between 2004 and 2022 were searched retrospectively for cats with antebrachial diaphyseal fractures treated with internal bone-plate fixation. In total, 49 cases were included from six referral hospitals, including one teaching hospital. Patient information was collated, including fracture configuration, location, repair method and clinical outcome as assessed by veterinary physical examination, radiography and owner questionnaire.

RESULTS

A total of 47 cats (mean age 4.2 years) were included. Fractures were located distally (24/49, 49%), proximally (13/49, 26.5%) and mid-diaphyseally (12/49, 24.5%). Dual bone fixation was used in 13/49 (26.5%) cases, with only 1/13 (7.7%) having major complications. By comparison, 4/36 (11.1%) of single plated fractures had major complications. Single bone fixation was 14.25 times more likely (95% confidence interval [CI] 2.07-97.99) to have a successful outcome (veterinarian-assigned score of 0) compared with dual bone fixation (P = 0.007). When evaluating owner-assessed outcomes, single bone fixation was 9.4 times more likely (95% CI 1.4-61.96) to have a successful outcome (owner score of 0) compared with dual bone fixation (P = 0.019).

CONCLUSIONS AND RELEVANCE

Fractures that were repaired with single bone fixation had a greater chance of a better outcome. Although the difference was not significant, there was a higher major complication rate and a lower minor complication rate for cases treated with single bone fixation compared with dual bone fixation. The majority of fractures were located in the distal diaphysis. Comminution of the fracture and concurrent orthopaedic issues did not significantly affect the outcome. Further prospective studies with standardised follow-up, radiographic assessment, surgeon and implants are required to truly assess the difference between dual and single bone fixation.

A Muscle Energy Techniques-Based Physiotherapeutic Intervention Protocol for Managing Nightstick Fracture: A Case Report

Distal ulna and radius fractures are the most frequent upper extremity fractures seen in emergency rooms. The axis of rotation for forearm pronation and supination runs through the radial head (proximal) and the ulnar fovea (distal). Throughout pronation and supination, the radius can rotate relative to the ulna, thanks to the way its head articulates with it. The ulna remains relatively stable during these movements. However, in cases of fractures of these bones, surgery to repair the radius is usually the best course of action for a distal ulna fracture. Most distal ulna fractures heal successfully with only conservative treatment once the radius is stabilized. To achieve the best results, medical personnel must take into account patient characteristics including age, level of activity, and aspirations. The majority of distal ulna injuries do not require surgery, but there are several circumstances where it is necessary. In therapeutic practice, muscle energy techniques (METs) are comparatively painless methods for restoring a restricted spectrum of motion. Malunion, reduced grasp, and other significant problems might result from a lack of understanding of this illness. The 48-year-old patient in the present study was reported to have sustained injuries to his left forearm in a road traffic accident (RTA) as he fell from his bike and slid during a traffic collision. X-ray imaging of the left forearm revealed an isolated ulnar shaft fracture. METs, isometric contractions, and active concentric and eccentric movements were all part of the physiotherapy intervention protocol to produce an active range of motion in the upper extremity. In this particular case, the specified physiotherapy management was found to be effective.

Characteristics of forearm refracture in adolescents

The purpose of this study was to evaluate characteristics of reinjury following forearm fractures in adolescents. An Institutional Review Board-approved retrospective cohort study of forearm fractures (ages 10-18 years) treated by a single academic pediatric orthopaedic group from June 2009 to May 2020 was conducted. All both bone forearm (BBFA) and radius or ulna primary and secondary injuries were included. We excluded open, surgically treated, physeal, epiphyseal, and radial head/neck fractures. Demographics, injury characteristics, and radiographic data were recorded. We evaluated associations of ipsilateral same-site refracture (RE-FRACTURE) versus ipsilateral or contralateral different-site forearm fractures occurring as secondary later injuries (OTHER). Thirty-three of 719 patients sustained a secondary forearm fracture (4.6%; mean age, 11.5 years; M:F, 5.6:1). RE-FRACTURES, compared with OTHER forearm locations, were associated with a sports mechanism at time of original injury ( P = 0.024) and mid-shaft position of fracture on the radius (77.6 vs. 29.8 mm from distal physis; P < 0.001) and ulna (72.0 vs. 27.2 mm from distal physis; P = 0.003). RE-FRACTURES also demonstrated increased radius to ulna distance between BBFA primary injury sites on anteroposterior (19.6 vs. 10.6 mm; P = 0.009) and lateral radiographs (19.6 vs. 10.5 mm; P = 0.020) compared with OTHER forearm locations. Residual angulation and fracture-line visibility were not significantly associated with secondary fracture. Ipsilateral same-site refractures tend to occur in adolescents within 1 year following treatment for widely spaced (>15 mm) and mid-shaft forearm fractures incurred during athletic activity. Further research may be warranted to evaluate biologic, bone health, or personality traits that may lead to secondary fractures of the pediatric forearm.

Reconstruction of oncologic upper extremity defects with fibula free flaps has high union rates and excellent functional outcomes

BACKGROUND

Limb salvage has better functional outcomes than amputation in the upper extremity. This can however be challenging after bony tumor resections.

METHODS

This is a retrospective case series of patients who underwent humerus, ulna, or radius reconstruction with a fibula free flap. Data were collected on demographics, oncologic history, surgical details, and complications. Functional outcome measures included the patient's ability to perform activities of daily living (ADL), presence of pain, and musculoskeletal tumor society (MSTS) score.

RESULTS

Over a 25-year period, 38 reconstructions were performed. The flap success rate was 97.5%. Bony union was obtained in 19 of 19 (100%) forearm reconstructions and in 15 of 19 (79%) humerus reconstructions (p = 0.10). All 19 forearm reconstruction patients and 18/19 humerus reconstruction patients were able to perform ADLs with no pain or only occasional pain. The MSTS scores were not significantly different between the humerus and forearm cohorts (27.1 vs. 27.3, p = 0.68). Functional outcomes were significantly better in limbs that achieved union (p < 0.001). Recipient and donor site complications occurred in 10 (26.3%) and 5 (13%) patients, respectively.

CONCLUSIONS

Oncologic upper-extremity reconstruction with fibula free flaps has excellent functional outcomes. Bone union is a predictor of superior limb function.

Exostosis of Ulna With Developmental Deformity of the Left Forearm: A Rare Case

This case report presents a rare occurrence of exostosis of the ulna associated with a developmental deformity of the left forearm in a 15-year-old female. The patient reported a history of trauma resulting in a supracondylar humerus fracture managed conservatively eight years prior. The patient presented with a two-year history of pain and swelling over the left forearm. Clinical examination revealed a firm, non-tender, immobile swelling closely associated with the ulna, accompanied by a 20-degree cubitus varus deformity and forearm shortening. Radiographs and computed tomography scans confirmed the presence of a solitary external bony protuberance over the ulna shaft, communicating with the medullary cavity. A preliminary diagnosis of osteochondroma was established based on clinical and imaging findings. The patient underwent extraperiosteal en bloc resection of the lesion under supraclavicular nerve block anesthesia. A histopathological examination confirmed the diagnosis. Postoperative physiotherapy was initiated, and at the one-month follow-up, the patient reported being pain-free. This case highlights the rarity of exostosis of the ulna with associated developmental deformity, emphasizing the importance of a comprehensive diagnostic approach. Early surgical intervention resulted in a successful outcome, underscoring the significance of timely management in improving patient outcomes and quality of life.

Biomechanics of plate fixation following traditional olecranon osteotomy versus novel proximal ulna osteotomy for visualizing a distal humerus injury

After a distal humeral injury, olecranon osteotomy (OO) is a traditional way to visualize the distal humerus for performing fracture fixation. In contrast, the current authors previously showed that novel proximal ulna osteotomy (PUO) allows better access to the distal humerus without ligamentous compromise. Therefore, this study biomechanically compared plating repair following OO versus PUO. The left or right ulna from eight matched pairs of human cadaveric elbows were randomly assigned to receive OO or PUO and repaired using pre-contoured titanium plates. Destructive and non-destructive mechanical tests were performed to assess stability. Mechanical tests on OO versus PUO groups yielded average results for ulna cantilever bending stiffness at a 90° elbow angle (29.6 vs 30.5 N/mm, p = 0.742), triceps tendon pull stiffness at a 90° elbow angle (28.2 vs 24.4 N/mm, p = 0.051), triceps tendon pull stiffness at a 110° elbow angle (61.9 vs 59.5 N/mm, p = 0.640), and triceps tendon pull failure load at a 110° elbow angle (1070.1 vs 1359.7 N, p = 0.078). OO and PUO elbows had similar failure mechanisms, namely, tendon tear or avulsion from the ulna with or without some fracture of the proximal bone fragment, or complete avulsion of the proximal bone fragment from the plate. The similar biomechanical stability (i.e., no statistical difference for 4 of 4 mechanical measurements) and failure mechanisms of OO and PUO plated elbows support the clinical use of PUO as a possible alternative to OO for visualizing the distal humerus.

Partial ulnar ostectomy, stereotactic body radiation therapy, and palliative radiation therapy as local limb sparing treatment modalities for ulnar tumors in dogs

Background

Information on dogs that undergo limb preserving local treatment for ulnar tumors is currently limited.

Objective

To describe the clinical characteristics and outcomes in dogs that underwent partial ulnectomy or radiation therapy (RT) for ulnar bone tumors, and to evaluate potential risk factors for outcomes as well as pre-treatment factors for association with treatment modality selected.

Animals

Forty client-owned dogs that underwent partial ulnectomy or RT for an ulnar tumor from July 2006 to July 2021.

Methods

The medical records database from a single institution were retrospectively reviewed, and data were recorded and analyzed.

Results

Radiation therapy was performed in 24 dogs, with 12 stereotactic body RT (SBRT) and 12 palliative RT (PRT) plans, and partial ulnectomy was performed in 16 dogs. Biomechanical complications occurred in 6/12 (50%) dogs that underwent SBRT, 6/12 (50%) dogs that underwent PRT, and 3/16 (18.8%) dogs that underwent ulnectomy. The majority of dogs had a good functional outcome following partial ulnectomy, and no dogs required surgical stabilization of the carpus even with lateral styloid process excision. Pathologic fracture occurred in 4/12 (33.3%) dogs following SBRT and 5/12 (41.7%) dogs following PRT. Local progression or recurrence was documented in 5/12 (41.7%) dogs that underwent SBRT, 2/12 (16.7%) dogs that underwent PRT, and 2/16 (12.5%) dogs that underwent ulnectomy. The overall median survival time was 198 days, and factors that were significantly associated with improved survival time included adjuvant chemotherapy administration and partial ulnectomy as local treatment method for dogs that received chemotherapy.

Clinical relevance

Both RT and ulnectomy were effective and well tolerated local treatment modalities for dogs with ulnar tumors.

Divergent Elbow Dislocation Associated with Ipsilateral Fractures of Ulnar Diaphysis and Radial Styloid Process in Adult: A Case Report

Introduction

The divergent elbow dislocation represents a rare lesion where the proximal radioulnar joint is torn and the distal part of the humerus goes between the radius and the ulna, the forearm dislocates posteriorly.

Case Report

We report the case of a 37-year-old male patient who had a traumatic divergent dislocation of the left elbow, associated with ipsilateral fractures of the ulnar diaphysis and the radial styloid process. The elbow joint was reduced under general anesthesia with internal fixation of the ulnar diaphysis fracture and a pinning of the radial styloid fracture. At 3 years of follow-up, the fractures were consolidated and the elbow was stable with a satisfying mobility.

Conclusion

The aim of our case report is to underline the diagnostic and therapeutic challenges of this complex lesion.

Predictors for operative treatment in pediatric proximal third both-bone diaphyseal forearm fractures in children include age and translation, but not initial angulation

Introduction

Proximal third diaphyseal fractures of the radius and ulna represent an onerous fracture pattern due to difficulty maintaining acceptable alignment with nonoperative management. Our aim was to identify the factors that increase the odds for a surgical treatment of these fractures. Recognizing these factors can raise awareness to patients who are more likely to require additional care and assist clinicians in counseling families, targeting treatment plans, and constructing follow-up protocols. We hypothesized that the age of the patient, the amount of initial fracture displacement, and the angulation of the fracture would predict the need for operative treatment.

Methods

We retrospectively reviewed 276 proximal third diaphyseal forearm fractures at a single tertiary care institution. All patients underwent a nonoperative treatment trial, and if failed continued to surgery. Following a univariate analysis, we constructed a binary multivariate logistic regression model that included age, initial translation, and initial angulation to assess the association between the tested variables.

Results

A regression model revealed that age (10 years and older, odds ratio: 8.2, 95% confidence interval: 3.9-17.24, p < 0.001) and radius translation of more than 100% (odds ratio: 7.06, 95% confidence interval: 2.69-18.52, p < 0.001) were associated with the need for surgical treatment. Initial fracture angulation lacked an association with a surgical treatment (odds ratio: 0.81 95% confidence interval: 0.38-1.74, p = 0.59).

Conclusion

Age above 10 years and 100% initial translation of the radius fracture increased the odds for an ultimate decision to perform a surgery. Initial angulation, although often being the most remarkable radiographic feature, was not associated with a nonoperative treatment failure. We recommend an initial reduction attempt after counseling patients and their families that there is a high rate of conversion to operative treatment when the above features are met.

Level of evidence

level III.

Return to sport after forearm fractures in children: A scoping review and survey

Purpose

A common question faced by clinicians is when a child may return to sport after treatment for a pediatric forearm fracture. There are few published recommendations and fewer supported by evidence. The aims of this study were to summarize existing published recommendation for return to sport after pediatric forearm fractures and to conduct a survey to determine usual clinical recommendations.

Methods

A scoping review was performed on Ovid MEDLINE, Cochrane Central Register of Controlled Trials, Embase, Scopus, and Google Scholar in accordance with the Joanna Briggs Institute guidelines. In addition, 64 orthopedic surgeons were anonymously surveyed asking for recommendations regarding return to sport after pediatric forearm fractures. Participants were to assume children were 9 years old and played a sport with an average risk of forearm injury.

Results

Twenty-two publications for return to sport were retrieved. Children with distal radius buckle fractures safely commonly returned to sport by 4 weeks after initial injury, while survey respondents recommended over 6 weeks. Survey respondents valued fracture stability the highest when making return to sport recommendations. Children with simple, metaphyseal, single-bone fractures were usually allowed to return to sport at 8-10 weeks post-injury. Diaphyseal and complete fractures were prescribed longer return to sport intervals. Australian respondents also prescribed longer return to sport intervals.

Conclusion

Children with distal radius buckle fractures may return to sport by 4 weeks after initial injury, sooner than recommended. Published recommendations remain limited for other fractures. However, our survey suggests children with simple, metaphyseal, single-bone fractures may return to sport at 8-10 weeks. Children with diaphyseal and complete fractures should abstain from sport for longer than metaphyseal and greenstick fractures, respectively.

Level of evidence

level V.

Bone-specific median age of hand-wrist maturation from Sudan

BACKGROUND

Maturation of bones in the hand-wrist region varies among individuals of the same age and among world groups. Although some studies from Africa report differences to other ethnic groups, the lack of detailed bone-specific maturity data prevents meaningful comparisons.

AIM

The aim of this study was to describe bone-specific maturity for developing hand-wrist bones in individuals in Khartoum, Sudan.

SUBJECTS AND METHODS

The sample was selected from healthy patients attending a dental hospital in Khartoum with known age and ancestry (males = 280, females = 330; aged between 3 and 25 years). Bones were assessed from radiographs of the left hand and wrist after the Greulich and Pyle Atlas (1959). Median ages of attainment for bone stages were calculated using probit analysis for each stage in males and females separately.

RESULTS

Maturity data for stages of the phalanges, metacarpals, carpals and radius and ulna in males and females are presented. Median ages in females were earlier compared to males for all stages. These results are largely earlier than previously published findings or where these could be calculated.

CONCLUSION

These results of individual maturity stages of phalanges, metacarpals, carpals and the distal epiphyses of the radius and ulna are useful to assess maturity in growing individuals from Sudan.

Kinematic analysis of forearm rotation using four-dimensional computed tomography

This study aimed to quantify forearm kinematics with a focus on the forearm rotation axis. Ten healthy volunteers were included in the study. One three-dimensional computed tomographic scan and two four-dimensional computed tomographic scans were done in all the arms to capture forearm joint motion. After image processing, the rotation axis and the movement of the radius with respect to various axes were quantified. The rotation axis was calculated using finite helical axis analysis and a circle fitting approach. The mean error of the rotation axis found through circle fitting was 0.2 mm (SD 0.1) distally and 0.1 mm (SD 0.1) proximally, indicating an improvement in precision over the finite helical axis approach. The translations of the radius along the ulnar axis and the forearm rotation axis were 2.6 (SD 0.8) and 0.6 mm (SD 0.9), respectively. The rotation of the radius around the radial axis was 7.2°. The techniques presented provide a detailed description of forearm kinematics.

Diagnostic Criteria and Treatment of Atypical Ulnar Fractures Associated With Prolonged Bisphosphonate Therapy: Multicenter Case Analysis

PURPOSE

Atypical ulnar fracture (AUF) related to prolonged bisphosphonate therapy is a rare complication. We propose diagnostic criteria of AUFs and present a treatment algorithm.

METHODS

Twelve AUFs in 10 patients were studied. The diagnosis of AUF was based on the case definition of atypical femoral fracture (AFF). We investigated clinical and radiographic characteristics of AUFs according to major and minor features of AFFs, and modified the case definition of an AFF to fit the characteristics of AUFs. All AUFs were treated surgically. The radiographic union of fractures was investigated, and delayed fracture healing was defined as a delay of 6 months or more.

RESULTS

The average point at which AUFs occurred was at a point 35.1% along the proximal diaphysis of the total ulnar length. All major features of AFFs were identified in the 12 AUFs. Among the minor features, generalized cortical thickening was observed in 6 AUFs, prodromal symptoms in 2 AUFs, bilateral involvement in 2 patients, and delayed fracture healing in 10 AUFs (5 delayed union, 5 nonunion). Initially, 11 of 12 AUFs were treated with plating, and 1 was treated with intramedullary nailing. Two nonunions were revised with sclerotic bone resections, bone grafts, and plate fixation. Finally, union was achieved in 9 AUFs.

CONCLUSIONS

The case definition of AFFs can be used for the diagnosis of AUFs, although some modifications must be included in the case definition. Plating is useful in managing AUFs, although sclerotic bone resections and bone grafts may be required. Atypical ulnar fractures occurred in patients who took bisphosphonates longer than AFFs or those whose bisphosphonates were discontinued a few years earlier. Therefore, physicians should be aware of AUFs in those patients and, if necessary, perform a screening test to look for atypical fractures in other bones.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic V.

Do "Anatomic" Distal Ulna Plating Systems Fit the Distal Ulna Without Causing Soft Tissue Impingement?

Background: Distal ulna fracture fixation plates commonly cause irritation, necessitating removal, due to the narrow area between the ulna articular cartilage and the extensor carpi ulnaris. This study defines the safe zone for plate application and determines whether wrist position affects risk of impingement. Methods: Four different distal ulna anatomic plates (Acumed, Medartis, Skeletal Dynamics, and Synthes) were applied to 12 cadaveric specimens. Safe zone size was measured in circumferential distance and angular arc. Impingement was examined in flexion and extension in neutral, pronation, and supination. Results: The distal ulna safe zone has dimensions of a 92° arc and perimeter circumference of 15 mm. Cumulative extensor carpi ulnaris (ECU) impingement occurred in 0% of the 6 simulated wrist/forearm positions for the Acumed plate, 22% for the Synthes plate, 31% for the Skeletal Dynamics plate, and 68% for the Medartis plate. Impingement was most common in supination. Likelihood of ECU impingement significantly decreased in the following order; Medartis > Skeletal Dynamics > Synthes > Acumed. Conclusion: The ECU tendon's mobility can cause impingement on ulnarly placed distal ulna plates. Intra-operative testing should be performed in supination. Take home points regarding each plate from the 4 different manufacturers: contouring of Medartis plates, when placed ulnarly, is mandatory. The Acumed plate impinged the least but is not designed for far-distal fractures. The Synthes plate is least bulky but not suitable for proximal fractures. The Skeletal Dynamics plate appeared the most versatile with a reduced incidence of impingement compared to other ulnarly based plates.

Does Surgery Improve Healing After Isolated Diaphyseal Ulna Fractures?

PURPOSE

Isolated diaphyseal ulna fractures can be treated nonsurgically or with open reduction and internal fixation (ORIF). It is unclear whether ORIF provides quicker and/or more predictable healing. The purpose of this study was to compare the healing characteristics of isolated diaphyseal ulna fractures after surgical and nonsurgical treatment.

METHODS

All patients treated for an isolated diaphyseal (distal- or middle-third) ulna fracture between 2010 and 2018, with a minimum of 3 months of follow-up, were identified. Electronic medical records were reviewed to record patient demographics, assess the treatments used, and compare outcomes. We determined healing and nonunion rates, complications, reoperations, and final radiographic fracture alignment.

RESULTS

Ninety-five patients were included with a median follow-up of 20 weeks. Of these, 56 patients were treated nonsurgically and 39 patients were treated with ORIF. At the time of the final follow-up, 51 of the 56 (91.1%) nonsurgically treated fractures had healed and 38 of the 39 (97.4%) surgically managed fractures had healed. There were 5 nonunions after nonsurgical treatment (8.9%) and 1 nonunion after ORIF (2.6%). Eleven patients (19.6%) treated nonsurgically required conversion to ORIF, whereas 4 patients (10.3%) treated with ORIF required reoperation. Middle-third fractures treated nonsurgically had a higher rate of nonunion (30.8%) compared with distal-third fractures treated nonsurgically (2.3%).

CONCLUSIONS

The healing characteristics of isolated ulnar shaft fractures do not appear to differ substantially between surgical and nonsurgical treatment. However, nearly 20% of the patients treated nonsurgically may require eventual ORIF. Distal-third fractures may be at a higher risk of conversion to ORIF, and middle-third fractures may be at a higher risk of nonunion.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Proximal Ulna Osteotomy for Complex Fractures of the Distal Humerus: A 3-Dimensional Laser Analysis and Comparison With Olecranon Osteotomy

PURPOSE

The current methods of distal humerus (DH) articular surface visualization only allow a limited view of the joint. This study describes an osteotomy procedure that increases the visualization of and access to the DH articular surface for fixation without compromising ligaments.

METHODS

Eighteen fresh-frozen human elbows (9 matched pairs) underwent proximal ulna osteotomy (PUO) or transverse olecranon osteotomy (OO) contralaterally. The visualized articular surface of the DH was demarcated, and the surface areas of the DH, capitellum, and trochlea were measured using 3-dimensional scanning. The angular arc of the articular surface of the capitellum and trochlea was measured using a goniometer.

RESULTS

The 3-dimensional scans showed that 87.6% of the total DH surface area was visualized using PUO versus 65.6% using OO. When the trochlea and capitellum surface areas were separated, 94.0% versus 75.9% of the trochlea and 74.8% versus 44.7% of the capitellum were visualized using PUO and OO, respectively. The goniometric angles demonstrated that 98.2% versus 70.9% of the trochlea and 75.1% versus 43.5% of the capitellum articular surface arc angles were visualized using PUO and OO, respectively. After PUO with further release of the flexor-pronator mass was performed, 100% of the DH articular surface was visualized.

CONCLUSIONS

Proximal ulnar osteotomy improves the visualization of the DH articular surface.

CLINICAL RELEVANCE

Proximal ulna osteotomy spares ligaments, avoids osteotomizing the greater sigmoid notch, involves more robust metaphyseal bone for potentially better fixation, and may permit DH arthroplasty without compromising primary ligamentous elbow stabilizers. Further clinical studies are needed to assess the utility of this type of osteotomy.

Supine correction index as a predictor for brace outcome in adolescent idiopathic scoliosis

Aims

The aim of this study was to assess the ability of morphological spinal parameters to predict the outcome of bracing in patients with adolescent idiopathic scoliosis (AIS) and to establish a novel supine correction index (SCI) for guiding bracing treatment.

Methods

Patients with AIS to be treated by bracing were prospectively recruited between December 2016 and 2018, and were followed until brace removal. In all, 207 patients with a mean age at recruitment of 12.8 years (SD 1.2) were enrolled. Cobb angles, supine flexibility, and the rate of in-brace correction were measured and used to predict curve progression at the end of follow-up. The SCI was defined as the ratio between correction rate and flexibility. Receiver operating characteristic (ROC) curve analysis was carried out to assess the optimal thresholds for flexibility, correction rate, and SCI in predicting a higher risk of progression, defined by a change in Cobb angle of ≥ 5° or the need for surgery.

Results

The baseline Cobb angles were similar (p = 0.374) in patients whose curves progressed (32.7° (SD 10.7)) and in those whose curves remained stable (31.4° (SD 6.1)). High supine flexibility (odds ratio (OR) 0.947 (95% CI 0.910 to 0.984); p = 0.006) and correction rate (OR 0.926 (95% CI 0.890 to 0.964); p < 0.001) predicted a lower incidence of progression after adjusting for Cobb angle, Risser sign, curve type, menarche status, distal radius and ulna grading, and brace compliance. ROC curve analysis identified a cut-off of 18.1% for flexibility (sensitivity 0.682, specificity 0.704) and a cut-off of 28.8% for correction rate (sensitivity 0.773, specificity 0.691) in predicting a lower risk of curve progression. A SCI of greater than 1.21 predicted a lower risk of progression (OR 0.4 (95% CI 0.251 to 0.955); sensitivity 0.583, specificity 0.591; p = 0.036).

Conclusion

A higher supine flexibility (18.1%) and correction rate (28.8%), and a SCI of greater than 1.21 predicted a lower risk of progression. These novel parameters can be used as a guide to optimize the outcome of bracing.

Cite this article: Bone Joint J 2022;104-B(4):495–503.

Characteristics of the length of the radius and ulna in children

OBJECTIVES

Congenital malformation, trauma, tumor, or metabolic disease can cause length deformity of the radius or ulna, affecting the appearance and function of the forearm. Osteotomy and lengthening with external fixation can obviously improve the length of the radius and ulna (LRU). However, the extent of lengthening required is still unclear. This study analyzed the LRU in children, to provide suggested standards for various orthopedic treatments.

METHODS

Normal LRUs were measured on X-ray images in children who came to hospital for emergency treatment, with measurements including anterior-posterior (AP) radiographs, lateral (LAT) radiographs, full LRU (total length), and LRU without the epiphysis (short length). Any cases of fracture or deformity affecting measurement were excluded. Three hundred twenty-six cases were divided into 16 groups according to age from 1 year old to 16 years old.

RESULTS

The earliest epiphyseal plate and ossification center were observed in the distal part of the radius at 1 year old, and in the proximal part at 3 years old in both boys and girls. In the ulna, at the distal end it was 6 years old in girls and 7 years old in boys, while in the proximal part ossification was observed at 9 years old in both boys and girls. The proximal epiphyseal plate of the ulna began to close on X-ray images at 12 years old in girls and 13 years in boys. LRU increased with age, and there was a strong positive correlation and consistent ratio between radius, ulna and age. In short length, the ratio of the length of radius to ulna (RLRU) ranged from 0.8941 to 0.9251 AP, from 0.8936 to 0.9375 LAT. In total length, RLRU ranged from 0.9286 to 0.9508 AP, and 0.9579 to 0.9698 LAT.

CONCLUSIONS

The length and epiphyseal ossification of the radius and ulna are associated with age. RLRU is also limited to a certain range and tends to remain stable with age. These characteristics have clinical significance for deformity correction of the forearm.

Missed Monteggia Fracture Dislocation in a 10-year-old Child - A Step-by-Step Approach to Properly Solving a Complex Problem: A Case Report

Introduction

Monteggia injuries are relatively rare in the pediatric population. They can be missed leading to complications arising from a chronic radial head dislocation. There is limited information about their proper management in the literature. Thus, their treatment remains controversial.

Case Report

We present a case of a 10-year-old boy who was examined in the orthopedic outpatient clinic of our hospital, due to limited range of motion of his left elbow and difficulty in extending his left thumb, after a forearm injury which occurred 9 months before and was initially treated conservatively. After appropriate imaging was obtained, a Bado type I Monteggia lesion was diagnosed. This was treated by open reduction of the head of radius, osteotomy of the ulna and lengthening using an external fixator, as well as annular ligament reconstruction by the use of synthetic tendon graft. The patient was followed up for 18 months after surgery and during his last examination showed very good clinical and functional results.

Conclusion

Missed Monteggia injuries in children are complex problems warranting a step-by-step approach. Their management with ulnar osteotomy, bone lengthening, and reconstruction of the annular ligament presents a viable option with excellent clinical, functional, and radiological outcomes.

Outcomes following Distal Radius Fractures with Preexisting Ulnocarpal Abutment

Background  Due to the commonality of distal radius fractures (DRFs), the potential impact of ulnocarpal abutment (UA) on patient outcomes is significant, whether it developed after or prior to injury. It is, therefore, important to consider whether preexisting UA has any impact on outcomes after an acute DRF. Questions/Purpose  The aims of this study were to determine if differences were present in (1) pain at final follow-up, (2) complications, and (3) unintended operations in patients with DRFs and either without or with preexisting radiographic UA. Methods  A single institution retrospective cohort study comparing patients treated either nonoperatively (43 patients) or operatively (473 patients) for DRFs between 5/1/2008 to 5/1/2018 was performed. Data included demographics, prior wrist pain or surgery, ulnar variance, select treatment data, and presence of pain, complication, or unintended operation by final follow-up. Statistical testing used Fisher's exact test and chi-squared test, with a significance level of 0.05. Results  The prevalence of preexisting UA was 14.0 and 15.6% in the nonoperatively- and operatively treated groups, respectively. In nonoperatively treated patients without or with UA, no differences in pain (37.8 vs. 33.3%, p  = 1.00) or complications were seen (13.5 vs. 50.0%, p  = 0.07). A higher unintended operation rate for nonoperatively treated DRFs with UA, compared with those without, UA was seen (5.4 vs. 50.0%, p  = 0.01). No differences in pain, complications, or unintended operations were seen between those without and with UA in the operatively treated group. Conclusion  Preexisting UA is not associated with pain, complications, or unintended operations after operative treatment of DRFs. Prospective studies further evaluating outcomes in nonoperatively treated DRFs with UA may be beneficial.

First-ever intraosseous ancient schwannoma of the proximal ulna successfully treated using the cement technique

Schwannoma or neurilemmoma is a common soft tissue neoplasm arising from the neural sheath of Schwann cells. However, intraosseous schwannoma is rare, accounting for less than 0.2% of primary bone tumours. Several variants of schwannoma have been reported; among them, intraosseous schwannoma with ancient change is extremely rare. This current report presents an extremely rare case of ancient intraosseous neurilemmoma. The patient presented with right elbow pain and disability. A radiolucent, well-defined, lobulated lesion with a thin sclerotic rim in the proximal ulnar metaphysis that had caused a pathological fracture was noted. The mass was surgically excised using marginal resection and bone curettage was undertaken. The bone deficit was grafted with hydroxyapatite and β-tricalcium phosphate and augmented with bone cement. There were no signs of any recurrence after 3 years. This is the first case of an ancient intraosseous schwannoma of the proximal ulna. Although rare, intraosseous schwannoma should be considered in the differential diagnosis of radiographically benign-appearing osseous tumours in the bone. The cement technique is recommended for the treatment of intraosseous schwannoma.

Reconstruction of coronoid process of the ulna: a literature review

As a pivotal part of the elbow joint structure, the coronoid process of the ulna plays a vital role in maintaining elbow joint stability. Loss of coronoid process height causes instability of the elbow joint depending on the fracture characteristics and size. The diagnosis and treatment of coronoid process fractures has gained widespread attention from orthopedic surgeons. Nevertheless, few reports have described reconstruction of coronoid process fractures and defects that affect elbow joint stability. Treatment of elbow joint instability induced by coronoid process defects is challenging because most cases are complicated by other elbow joint injuries. Moreover, the clinical efficacy remains unclear. The present narrative review was performed to examine the research progress on reconstruction of the coronoid process. The findings of this review provide evidence for clinical repair and reconstruction of coronoid process defects and contribute to the published literature on this topic.

Case Report: Prophylactic Plate Fixation for Incomplete Atypical Ulnar Fractures Resulting From the Use of Denosumab for Bone Metastases

Patients with bone metastases are treated with long-term bone resorption inhibitors such as bisphosphonates and denosumab. However, resorption inhibitors have been known to cause fractures, such as atypical femoral fractures (AFFs). In recent years, there have been an increasing number of reports of atypical ulna fractures (AUFs) caused by bone resorption inhibitor usage. Treatment of AUFs is complicated, especially when they occur in patients with bone metastases, because it is difficult to discontinue bone resorption inhibitor treatment without the risk of aggravating metastatic lesions. Prophylactic surgery is recommended in AFFs when fractures are predicted, but there are few reports of prophylactic surgery for AUFs. Here, we report a case of incomplete AUF in a 74-year-old woman which was surgically treated with prophylactic plate fixation. The patient had been using denosumab for 6 years to treat bone metastases due to thyroid cancer. After surgery, no fractures were observed for 2 years without discontinuing denosumab, and her forearm function was adequate. AUFs are rare and difficult to treat, so oncologists who treat bone metastases need to pay special attention to diagnose this incomplete AUF before the fracture worsens. We believe that detection of a possible fracture and prophylactic surgery can improve prognosis.

Rotational Anatomy of the Radius and Ulna: Surgical Implications

PURPOSE

The rotational anatomy of the forearm bones is not well defined. This study aims to further the understanding of the torsion of the radius and ulna to better guide treatment.

METHODS

Computed tomography images of 98 cadaveric forearms were obtained and 3-dimensional models of the radius and ulna were generated and analyzed. The rotation of the radius was evaluated by comparing the orientation of the distal radius central axis (DRCA) with the volar cortex of the distal radius (DR) and biceps tuberosity (BT). The rotation of the ulna was evaluated by assessing the orientation of the ulnar head with respect to the proximal ulna.

RESULTS

The DR volar cortex pronates from distal to proximal. The BT was 43.8° ± 16.9° supinated from the DRCA (range, 2.7°-86.5°). The mean difference in rotation between contralateral biceps tuberosities was 7.0° ± 7.1°. The volar cortex of the DR was 12.6° ± 5.4° supinated compared with the DRCA. The ulnar head was pronated 8.4° ± 14.9° with respect to the greater sigmoid notch (range, 50.3° pronation-22.0° supination).

CONCLUSIONS

The BT has a variable orientation relative to the DR, but it is generally located anteromedially in a supinated arm or 136° opposite the radial styloid. Understanding the rotational anatomy of the radius and ulna can play an important role in surgical planning and implant design. The rotational anatomy of the radius and ulna varies significantly between individuals, but is similar in contralateral limbs.

CLINICAL RELEVANCE

Distal radius volar cortex rotational anatomy can help guide treatment of DR fractures and malunions as well as assist in positioning of wrist arthroplasty implants, particularly in the presence of bone loss. The side-to-side similarities demonstrated in this study should be helpful in managing patients with segmental bone loss or fracture malunion and those requiring joint reconstruction.

SUCCESSFUL REPAIR OF ANTEBRACHIAL FRACTURES WITH EXTERNAL SKELETAL FIXATION IN THREE MACROPODS

Three captive macropods comprising three different species sustained unilateral antebrachial fractures. All fractures were assumed to be trauma related, although the specific circumstances surrounding each case was unknown. Each fracture was surgically repaired with type Ia (unilateral, monoplanar) external skeletal fixators, which were all removed approximately 3 mo postoperatively. Although each animal experienced at least one complication, all animals showed adequate bridging and remodeling at the fracture sites and had good-to-excellent return to normal function after fixator removal. This case series is the first to describe the successful repair of antebrachial fractures using external skeletal fixation in captive macropods and details some of the complications that can occur with postoperative management of captive animals.

Anatomical relationship between the morphology of the styloid process of the ulna and the attachment of the radioulnar ligaments

The radioulnar ligaments are the major stabilizers of the distal radioulnar joint under dynamic loading; however, anatomical detail regarding their attachment on the middle and distal thirds of the styloid process of the ulna remains unclear. Because previous anatomical studies included only old cadavers, their anatomical findings might not reflect the morphological features of younger and healthy specimens. This study investigated the anatomical features of the distal ulna, particularly the styloid process, to determine the attachment of the radioulnar ligaments to the styloid process and verified their direction and attachment to the styloid process in younger and healthy donors using magnetic resonance imaging (MRI). We investigated the morphological features of the distal ulna of 12 cadaveric wrists using micro-computed tomography (micro-CT). We also visualized and measured the distribution of the cortical bone thickness. We histologically analyzed three specimens in the axial plane and macroscopically analyzed seven specimens to examine the attachment of the radioulnar ligaments to the styloid process. In addition, we evaluated five wrists from living volunteers using 3.0 Tesla MRI. The distal ulna has a ridge on the dorsoradial aspect of the styloid process that corresponds to the attachment of the radioulnar ligaments. Micro-CT images after data processing revealed that the cortical thickness of the dorsoradial quadrant was thicker than that of the other quadrant at the proximal slice of the styloid process (p < 0.01), and that of the dorsoulnar (p = 0.021) and ulnopalmar (p < 0.01) quadrants at the middle slice. Histological analyses showed that the radioulnar ligaments were attached to the middle and distal thirds of the styloid process via chondral-apophyseal entheses. The direction of the fiber was dorsal in the middle third of the styloid process and changed to palmar in the distal third of the styloid process. The direction and attachment of the radioulnar ligaments on the styloid process were confirmed using MRI for younger and healthy participants. The radioulnar ligaments were attached to the dorsoradial ridge of the styloid process, which was confirmed by cortical bone thickening, histology at the attachment sites, and in vivo MR imaging. The directions of the radioulnar ligaments sterically intersected, which would satisfy both slipping stability and rotational mobility. These anatomical findings may provide the basis for biomechanical consideration of distal radioulnar joint stabilization.

Are entheseal changes and cross-sectional properties associated with the shape of the upper limb?

OBJECTIVES

Reconstruction of the activity of past human populations can be carried out using various skeletal markers; however, the relationship between these methods is not fully understood. Therefore, the main aim of this article is to analyze the relationship between entheseal changes, cross-sectional properties, and variability in the shape of the upper limb.

MATERIALS AND METHODS

The analyzed material consisted of CT images of 71 right scapulae, humeri, and ulnae belonging to the same individuals from a mediaeval population located in Poland. For each series of bones for the same individual, skeletal markers such as: cross-sectional properties, entheses and shape variation were assessed. Next, correlations between these three skeletal indicators were calculated.

RESULTS

In general, the models showed that only sex influences entheses. Multivariate regression revealed significant correlation only between ulnar auricular surface shape and two types of mean score for entheses.

DISCUSSION

The findings are inconsistent and stand in contradiction to other research; therefore, we suggest that an assessment of individual activity should be carried out, using as many post-cranial elements as possible and a variety of methods. This approach will ensure more accurate reconstruction of the activity levels and patterns of archeological groups.

Release Rates and Complications for Birds of Prey With Antebrachial Fractures at a Veterinary Teaching Hospital

A retrospective case series that included 253 free-ranging birds of prey admitted to a rehabilitation center was conducted to describe the treatment and outcome of antebrachial fractures. Medical records from birds of prey belonging to 21 species admitted with antebrachial fracture between 1989 and 2015 at the University of California, Davis, were reviewed. Species distribution on admission, treatment, outcome, and complications were described by fracture category and species. Among 134 birds treated after initial triage on the day of admission, 4 bone/ wing categories were identified: 83 birds had an ulnar fracture only; 18 birds had a radial fracture only; 28 birds had a concomitant fracture of the radius and ulna on the same wing; and 5 birds had bilateral antebrachial fractures. Logistic regressions were performed to determine which factors were associated with a positive outcome within each of these 4 categories. Among birds having only an ulnar fracture, those with a closed fracture were significantly more likely to be released than birds with open fractures (P = .03; odds ratio = 5.43, 95% confidence interval: 1.29-28.12). In addition, birds with a fracture of the middle third of the ulna were significantly more likely to be released than birds diagnosed with a single fracture of the proximal third of the ulna (P = .02; odds ratio = 4.54, 95% confidence interval: 1.35-16.64). No significant prognostic factor was detected in other fracture categories.

Retrograde Fixation of the Ulna in Pediatric Forearm Fractures Treated With Elastic Stable Intramedullary Nailing

Introduction

This study analyzes the outcomes of retrograde fixation of the ulna in pediatric forearm fractures treated with elastic stable intramedullary nailing (ESIN).

Materials and Methods

A retrospective analysis was conducted by reviewing patient records of forearm fractures treated with ESIN by retrograde fixation. The study included 30 children (26 boys and 4 girls). The mean age at the time of injury was 11.7 years (range: 6.6 to 14.3 years). The technique is described. All patients were followed up until hardware removal.

Results

The mean time for fracture healing was 5.3 weeks (range: 4 to 8.8 weeks). The mean time for nail removal was 6.6 months (range: 5 to 10 months). There were five cases with rotation deficits, one of which was a re-fracture.

Conclusions

When antegrade nailing is performed, the ulna is sometimes complicated by non-union as well as entry point irritation. We did not encounter such complications. Retrograde fixation of the ulna in pediatric forearm fractures treated with ESIN is a safe and effective alternative to common fixation (antegrade ulnar fixation) and offers technical advantages.

A cadaveric study of radial and ulnar bowing in the sagittal and coronal planes

BACKGROUND

This study provides a comprehensive, full-length assessment of radial and ulnar bowing in anteroposterior (AP) and sagittal planes.

METHODS

Radial and ulnar AP and lateral bowing were assessed using orthogonal digital photographs of 211 randomly selected cadaveric bilateral forearms (422 radius, 422 ulna bones) from a well-preserved osteologic collection.

RESULTS

In the radial AP plane, an apex-radial bow was present at a mean of 58% of bone length (slightly distal to midpoint), with a mean depth of 1.3 cm. In the radial lateral plane, an apex-dorsal bow occurred at a mean of 45% of bone length, with a mean depth of 0.8 cm. In the ulnar AP plane, apex-radial bow occurred at a mean of 32% of bone length with a mean depth of 1.0 cm. In the ulnar lateral plane, the majority of specimens (81%) had an apex-dorsal bow, whereas 19% had a reverse (apex-volar) bow. Lateral ulnar bow was located at a mean of 33% of bone length with a mean depth of 2.0 cm, with 36% of specimens possessing a lateral bow located at 35% or more distal along the ulna. Side-to-side differences for bow location and depth were less than 2% of bone length.

CONCLUSIONS

Ulnar lateral bow was found to be more distal than in previously published works, which analyzed only the proximal ulna, and this study describes a reverse ulnar bow in 19% of specimens. This demonstrates lateral ulnar morphology to be more variable than previously defined with minimal side-to-side variability, which are important considerations for fracture fixation and elbow arthroplasty.

Ulnar Shortening Osteotomy: Our Experience

Objective  The objective of the present study was to evaluate the clinical and radiographic results of our series regarding ulnar shortening osteotomy, as well as to briefly review the pathology, indications and surgical options of ulnocarpal conflict. Methods  We performed a retrospective analysis of consecutive patients who were treated with ulnar shortening osteotomy between January 2012 and June 2017 at our hospital. We clinically evaluated pain, articular range of motion, grip strength and functional outcomes using the quick-DASH questionnaire. We radiographically measured the pre- and postoperative ulnar variance and the shortening performed. Results  We identified eight operated patients, and it was possible to evaluate seven of them. Pain decreased in this population (visual analogue scale [VAS] score changed from 7 to 2.6, p  < 0.05), there was a decrease in quick-DASH (64 to 28, p  < 0.05) and we found a decrease in the articular amplitude ∼ 7° for flexion ( p  = 0.2), and of 5.5° for supination ( p  = 0.3), as well as decreasing grip strength to about 86% on the contralateral side ( p  = 0.07). The ulnar variance changed from a mean of + 5.5 mm to - 1.1 mm ( p  < 0.05). Two out of 8 patients (25%) presented plaque-related symptoms and one of them underwent a new intervention to extract the material. Conclusions  Ulnar shortening osteotomy is an effective surgical procedure both in the treatment of ulnocarpal conflict and in the discharge of the ulna. The results presented agreement with other results published in the literature, with good clinical and radiographic results.

Sterile osteomyelitis in the ulnar diaphysis of a young indoor cat

Case summary

A 3-year-old neutered male indoor British Shorthair cat was referred for a 2-week history of intermittent right forelimb lameness. Radiographic examination showed a diaphyseal monostotic, expansile, fusiform, lytic lesion in the right ulna. CT further defined the lesion and also demonstrated ipsilateral pulmonary consolidation. Histology was conclusive of osteomyelitis, and microbiology and fluorescence in situ hybridisation analysis (FISH) were negative on aerobic and anaerobic bacterial culture, as well as fungal culture. Clinical and radiographic improvement was seen after anti-inflammatory treatment and a short initial period of antibiosis.

Relevance and novel information

This is an unusual monostotic diaphyseal cortical location for osteomyelitis in cats and, moreover, may represent a rare case of sterile osteomyelitis. To our knowledge, non-traumatic osteomyelitis in this location in cats has not been reported in the veterinary literature.

Estimation of Body Stature Using the Percutaneous Length of Ulna of an Individual

Objective To explore the association between the percutaneous length of ulna and height of that individual and to formulate a gender-specific formula. Methods This is a cross-sectional study conducted at the Nishtar Medical University, Multan from May 1 2019 to July 1 2019. Length of ulna and body height were measured for 100 participants, including an equal number of males and females. Means of age, length of ulna and body height were compared between both genders. Regression coefficient, Pearson correlation coefficient and constant were calculated and regression formulae were formed for calculating height from length of the ulna for males, females, and the whole study group, separately. Data analysis was done using Statistical Package for the Social Sciences; version 23 (SPSS Inc., Chicago, IL); p≤0.05 was considered statistically significant. Results Pearson correlation coefficient, regression coefficient, constant were statistically significant for males, females, and the whole study group (p<0.001). Regression equations that were devised after analyzing the data to estimate the stature from ulna length are as follows: for the whole study group: 42.830+4.671 (length of ulna); for males: 70.369+3.698 (length of ulna); for females: 18.562+5.617 (length of ulna). Conclusion The length of ulna provides a reliable and relatively accurate means for estimating an individual's height. Regression formulae devised will be of practical use for forensic scientists, anthropologists, archeologists, clinicians and anatomists for estimating the stature from the length of the ulna.

The Radioulnar Distance at the Level of the Radial Tuberosity

Ruptures of the distal biceps brachii tendon are generally treated operatively due to their loss of supination and flexion force. A mechanical impingement at the insertion of the tendon at the radial tuberosity is discussed to play a role in the etiology of this injury. The aim of this study was to present a detailed, three-dimensional anatomical analysis of the radioulnar space at the radial tuberosity. A total of 166 imprints of the radioulnar space in neutral rotation and pronation from 84 cadaveric specimens of both arms using silicone impression material were produced for this study. Imprints were cut in slices of 3 mm and digitally measured after picture acquisition using a high-resolution digital camera. Distances were grouped into a proximal, central, and distal groups and used for correlation to morphometric data at the elbow (radial head diameter, ulna and radius length) as well as volume calculation. The mean radioulnar distance was 8.8 ± 4.0 mm in neutral rotation and 7.8 ± 3.9 mm in pronation. In pronation, the central zone was the smallest whereas in neutral rotation the proximal zone was the smallest. The volume of the radioulnar space did not reduce significantly during pronation. Little space is provided for the insertion of the distal biceps brachii tendon especially during pronation. This could play a role in the etiology of distal biceps brachii tendon ruptures and should be considered in the fixation after rupture of the tendon. Clin. Anat., 33:661-666, 2020. © 2019 Wiley Periodicals, Inc.

Analysis of Radiographic Relationship between Distal Radius, Ulna, and Lunate

Background  Wrist anatomy variability is associated with differing susceptibility to pathology. For example, a flat radial inclination is associated with Kienbock's disease. Lunate facet inclination (LFI) also exhibits variability. Its relationship with other wrist features is poorly documented. Purposes  We tested the hypothesis that high LFI is associated with increased uncovering of the lunate, negative ulnar variance (UV), and type 2 lunates to balance forces across wrists. Methods  In total, 50 bilateral and 100 unilateral wrist posteroanterior radiographs were reviewed. Lunate type, lunate uncovering index (LUI), lunate tilting angle (LTA), UV, and sigmoid notch angle (SNA) were measured, and correlation with LFI was assessed on 150 right wrist radiographs followed by an assessment of differences based on lunate morphology. Symmetry of 50 bilateral wrists was assessed. Results  There was no correlation of LFI with lunate morphology, LUI, and LTA. There was a low correlation of LFI with SNA and UV. There was an inverse relationship between UV and SNA. Wrists with type 2 lunates had more oblique sigmoid notches and higher LTA in comparison to wrists with type 1 lunates. Side-to-side comparison revealed strong correlation except for LUI, which exhibited moderate correlation. Conclusions There is no correlation between LFI, LUI, and lunate morphology. Type 2 lunates are associated with higher LTA and more oblique SNA. Wrists were symmetrical. Clinical Relevance  Factors other than lunate morphology are essential in balancing forces across wrists. A better understanding of soft tissue and other factors will improve the understanding of wrist biomechanics and pathology. Contralateral wrist radiographs can guide reconstructive surgery.

Madelung's deformity: capitate-related versus ulna-related measurement methods

Several investigators have defined measurements for Madelung's deformity based on the distal radius or on the longitudinal ulnar axis to avoid the distorted distal radius and its lunate fossa. However, errors may occur in severe cases because of ulnar deformity and displacement. We quantified seven established measurements for Madelung's deformity relying on the central axis of the capitate. The inter- and intrarater reliability of the capitate-related and the ulna-related techniques were compared. We observed a higher inter- and intrarater reliability for the capitate-related method than for the ulna-related method. Better agreement was also observed for measurements of distance than for measurements of angles. However, the palmar tilt angle measurement method was neither reliable nor reproducible. The capitate-related technique can help to accurately determine the severity of Madelung's deformity, assist in surgical planning and identify the prognosis. Level of evidence: III.

Single injection of PTH improves osteoclastic parameters of remodeling at a stress fracture site in rats

Stress fractures (SFx) result from repetitive cyclical loading of bone. They are frequent athletic injuries and underlie atypical femoral fractures following long-term bisphosphonate (BP) therapy. We investigated the effect of a single PTH injection on the healing of SFx in the rat ulna. SFx was induced in 120 female Wistar rats (300 ± 15 g) during a single loading session. A single PTH (8 µg.100g^-1 ) or vehicle (VEH) saline injection was administered 24 h after loading. Rats were divided into four groups (n = 15) and ulnae were examined 1, 2, 6, or 10 weeks following SFx. Two Toluidine Blue and TRAP-stained sections of the SFx were examined for histomorphometric analysis using Osteomeasure™ software. An increase in osteoclast number (N.Oc) and perimeter (Oc.Pm) was observed two weeks following PTH treatment (p < 0.01). At 6 weeks, bone formation was the main activity in BMUs. At 10 weeks, the proportion of healing along the SFx line remained 50% greater in PTH groups (p = 0.839), leading to a 43% reduction in the porosity area of BMU (p = 0.703). The main effect of time was a significant variable along the entire SFx remodeling cycle, with significant interactions between time and treatment type affecting (N.Oc) (p = 0.047) and (Oc.Pm) (p = 0.002). We conclude that a single PTH injection increases osteoclastogenesis by the second week of the remodeling cycle in a SFx in vivo. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Comparative Study of Early Health Care Use after Forearm Corrective Osteotomy

Background  Bone reconstruction is frequently required for corrective osteotomy of the forearm long bones. Studies have evaluated long term outcomes but not the impact of these procedures on early postoperative complications and health care utilization. Questions/Purposes  This study evaluated the early postoperative health care utilization following corrective osteotomy of the radius and/or ulna. Patients and Methods  The American College of Surgeons' National Surgical Quality Improvement Program (NSQIP) was the primary data source to perform a comparative statistical analysis of the bone autograft and nonautograft (allograft, graft substitute, or no graft) procedures. We performed a review of the NSQIP database (2005-2013) to evaluate patients who underwent a corrective osteotomy of the radius and/or ulna. Results  There were 362 cases; autograft ( n  = 117) and nonautograft ( n  = 245). There were no significant differences with demographics or comorbidities. The majority of cases were outpatient surgeries and there were no significant differences in anesthesia time, operative time, or hospital length of stay. Overall, the average length of stay was 0.6 days, readmission rate was 2%, and the total complication rate was 1% and there was no statistically significant difference between reconstruction groups. Harvesting of autograft was not associated with the overall 30-day complications and specific markers of health care utilization. Conclusions  Our results are derived from the heterogeneous hospital setting of NSQIP contributing centers. The health care utilization and 30-day complications are low following corrective osteotomy of forearm long bones and autograft harvest did not influence the health care utilization. Level of Evidence  Therapeutic Level II.

Isolated Regan-Morrey Type III Fracture of the Ulnar Coronoid Process: A Report of Two Cases

Introduction:

Fracture of the ulnar coronoid process is uncommon. It is commonly associated with posterior dislocation of the elbow, but it may also present as an isolated fracture. In general, all ulnar coronoid process fractures with elbow joint instability and large fracture fragments are fixed surgically. We report two cases of the rare isolated Regan-Morrey type III ulnar coronoid process fractures and their outcomes.

Case Report:

Case Report 1: Mrs P, a 27-year-old right-hand dominant female, was involved in a motor vehicle accident (MVA) and sustained an isolated Regan-Morrey type III ulnar coronoid process fracture. In view of the large coronoid process fragment causing elbow joint instability, she underwent an open reduction and internal fixation when the elbow swelling had subsided. An anterior approach was used to identify the fracture fragment and it was fixed with two half-threaded cancellous lag screws with washers to achieve an anatomical reduction. Postoperatively, she recovered with excellent outcome based on the Mayo elbow performance score (MEPS).

Case Report 2: Mr M, a 23-year-old right-hand dominant gentleman, was involved in a MVA and sustained an isolated Regan-Morrey type III ulnar coronoid process fracture. During examination under general anesthesia, passive range of the movement of his right elbow was noted to be <90°due to the impaction of the fracture fragment. An open reduction through an anterior approach was performed and Kirschner wires were inserted to fix the coronoid process fracture. Kirschner wires were opted for the ease of post-operative removal as the patient was not keen to have a retained implant after recovery. He recovered with good outcome based on the MEPS.

Conclusion:

Isolated fracture of the ulnar coronoid process is rare. Open reduction and internal fixation is mandatory for patients with coronoid process fracture and unstable elbow joint to achieve good functional outcomes.

Extensor Carpi Ulnaris Tenodesis Versus No Stabilization After Wide Resection of Distal Ulna Giant Cell Tumors

BACKGROUND

The necessity of stabilizing the residual ulnar stump after distal ulna tumor resection remains controversial. The authors retrospectively compared the outcome of patients who underwent wide resection of distal ulna giant cell tumors (GCTs) and reconstruction with tenodesis of the extensor carpi ulnaris (ECU) or without reconstruction.

METHODS

Between 2007 and 2015, 9 patients (6 females, 3 males; mean age, 36.8 years; range, 24-65 years) who underwent distal ulna resection for GCT of bone were retrospectively reviewed. The mean resection length was 8.1 cm. Five patients had no reconstruction, whereas 4 patients had stabilization of the ulnar stump using ECU tenodesis. With a mean follow-up of 3.6 years (2-9 years), the functional outcome using the quick Disability of Arm, Shoulder and Hand (DASH) score; Musculoskeletal Tumor Society score and grip strength; as well as the oncological outcome were evaluated.

RESULTS

Musculoskeletal Tumor Society functional scores were more than 24 in 7 patients and 20 to 24 in 2 patients (mean, 27.6 or 92%). Quick DASH scores ranged from 0 to 27.3 (mean, 11.1). In both groups, similar scores were observed ( P > .5). No patient had instability or pain related to the stump. There was no ulnar translation or subluxation of the radiocarpal joint. Grip strength in the operated hand, controlled for handedness, was 11% less than in the contralateral hand, although there was no difference between groups ( P > .4). All patients were disease-free at the latest follow-up.

CONCLUSIONS

The distal ulna may be widely resected with or without stabilization of the residual ulnar stump, yielding satisfactory local disease control and functional outcome.

The mechanical hypothesis of septal aperture formation tested in an early medieval population from Ostrów Lednicki (Poland)

The aetiology of septal aperture formation is still an open question. The influence of bone robusticity, osteoarthritis, osteoporosis, and the size and shape of ulnar processes has been discussed. Some researchers have shown that weaker muscles lead to greater joint hypermobility, the impingement of ulnar processes on the humeral lamina, and, consequently, septal aperture formation. Assuming this theory is correct, the question is whether flexion or extension or both play a role in septal lamina perforation. The aim of the study was to examine the mechanical hypothesis of septal aperture formation in samples of skeletal material derived from an early medieval cemetery in Ostrów Lednicki (Poland). A total of 136 pairs of bones (humeri and ulnae) were examined. Septal aperture was scored as present or absent. Entheseal changes in ulna were used as markers of activity patterns, especially involving elbow extension and flexion. Entheseal changes were assessed based on a three-point rating scale. A significant negative correlation between septal aperture and triceps muscles was noted in right bones in females (τ = -0.331) and in both sexes combined (τ = -0.322). The relationship between septal aperture and the brachialis muscle was positive but non-significant. This means that looser triceps lead to greater looseness of the elbow, greater protrusion of the olecranon process, and consequent septal aperture formation. Different results were obtained for the brachialis, which may suggest that forearm flexion does not significantly affect septal lamina perforation.

A Modification of Internal Bone Transport Method for Reconstruction of Nonunion of Forearm

BACKGROUND

Defects of bone and soft tissue occur frequently after high-energy trauma, infections, and tumor resection. Treatment options are limited and outcomes are controversial in nonunion. Classical reconstruction methods are challenging. We describe a method of internal bone transport for treatment of complicated nonunion of the forearm. This method permits axial and internal bone transport without harming the distorted and complex neurovascular anatomy or soft-tissue envelope.

MATERIALS AND METHODS

Five patients (mean age, 27 years) with defect nonunion (3 ulna, 2 radius) were treated. Mean preoperative defect size was 36 mm, mean shortening was 14 (0-30) mm, and the extent of surgical resection was 24 (20-40) mm. Total bone loss due to defect, resection, or shortening was 74 mm. According to Paley classification, two of the patients had B1, and three had B3 defect nonunion. This study treats defect nonunion of the forearm using an internal bone-transport method. Our method involved cannulated screws, a cerclage wire, and a circular fixator being used in combination. When transportation was completed, internal fixation of the docking site with a plate and screws was done, with bone grafting after fixator removal. Bone healing and functional outcomes were assessed with radiographs and disabilities of the arm, shoulder, and hand (DASH) scores, respectively.

RESULTS

Mean followup was 67.6 months. Solid osseous union and functional improvement were achieved in all cases. Mean bone loss was 66 mm, mean fixator time was 131.8 days, the lengthening index was 1.3 days/mm, and the fixator index was 2.1 days/mm. DASH score was 82.2 before treatment and 15.36 after treatment.

CONCLUSIONS

Using our method, internal bone transport and progressive axial docking of defects can be done with minimal effects on surrounding neurovascular arrangements and soft tissues. Size of fixators can be decreased and formation of painful scar tissue can be avoided.

Reliability of upper-limb diaphyseal mineral and soft-tissue measurements using peripheral Quantitative Computed Tomography (pQCT)

OBJECTIVES

To quantify between-day reliability of upper-body diaphyseal measurements (radius, ulna, humerus) using peripheral Quantitative Computed Tomography (pQCT).

METHODS

Fourteen males (age: 25.8±2.3 years,) underwent repeat pQCT scans (one to two days apart) at mid-shaft ulna (60%), mid-shaft radius (60%) and mid-shaft humerus (50%) cross-sections of the non-dominant limb. Intraclass correlation coefficients (ICC) and coefficients of variation (CV) were determined for musculoskeletal morphology variables.

RESULTS

Reliability was excellent (ICC: 0.76-0.99; CV: 1.3-7.3) at all sites for bone mass, stress-strain index, endocortical and pericortical radius, endocortical volumetric bone mineral density (vBMD), muscle area, total area, non-cortical area, and cortical area. Reliability was good to excellent (ICC: 0.58-0.80; CV: 0.6-3.7) for polar vBMD and mid-cortical vBMD; fair to excellent (ICC: 0.30-0.88; CV: 0.5-8.0) for muscle density and cortical density; and fair to good (ICC: 0.25-0.60; CV: 3.4-7.6) for pericortical vBMD. Average reliability across the three sites was excellent (ICC ≥0.77; CV ≤8.0).

CONCLUSIONS

Overall between-day reliability of pQCT was excellent for the mid-shaft ulna, radius and humerus. pQCT provides a reliable and feasible body composition and skeletal morphology assessment tool for upper limb longitudinal investigations in scientific and clinic settings.