Successful Reimplantation of Extruded Ulnar Diaphyseal Segment: A Case Report and Review of Literature.

CASE: A 32-year-old man presented with a type II open both-bone forearm fracture and segmental bone loss because of complete extrusion of a diaphyseal fragment (3 cm) of ulna. The patient presented to our level 1 trauma center after a motor vehicle collision. The extruded segment underwent sterilization and immediate reimplantation with internal fixation approximately 6 hours after arrival. Our patient achieved union by 7-month follow-up, demonstrated excellent functional outcomes, and was free from infection at 1-year follow-up. CONCLUSION: In select cases, successful reimplantation can be achieved by meticulous debridement, sterilization, and immediate reimplantation with internal fixation.

Complex Fractures of the Radial and Ulnar Shaft.

SUMMARY: Successful management of radial and ulnar shaft fractures is an essential skill for all orthopaedic surgeons. The frequent presentation of these injuries coupled with the nuanced anatomic considerations that must be observed for successful outcomes dictate that these injuries require a thorough understanding by the treating surgeon. Intraoperative care to restore the anatomic radial bow and rotation is essential for the resumption of functional forearm rotation postinjury. Often, problems arising during the operative treatment of radial and ulnar shaft fractures come in predictable patterns that can be mitigated with preoperative planning and sound technique. Cases of increased complexity with segmental bone defects and soft tissue defects require a variety of advanced reconstructive techniques.

Subsequent fracture risk in Norwegians and immigrants with an index forearm fracture: a cohort study.

The current study investigated subsequent fracture risk following a forearm fracture in three country of birth categories: Norway, Europe and North America, and other countries. Subsequent fracture risk was modestly higher in Norwegian-born individuals compared to the two other groups. Secondary fracture prevention should be recommended regardless of country background. BACKGROUND: Fracture risk is higher in patients with a previous fracture, but whether subsequent fracture risk differs by origin of birth is unknown. This study explores subsequent fracture risk in patients with an index forearm fracture according to region of birth. METHODS: Nationwide data on forearm fractures in patients ≥ 18 years in 2008-2019 were obtained from the Norwegian Patient Registry and Statistics Norway. Index fractures were identified by ICD-10 code S52, whereas subsequent fractures included any ICD-10 fracture code. Data on country of birth were from Statistics Norway and included three regional categories: (1) Norway, (2) other Europe and North America and (3) other countries. Direct age standardization and Cox proportional hazard regression were used to analyse the data. RESULTS: Among 143,476 individuals with an index forearm fracture, 35,361 sustained a subsequent fracture. Norwegian-born forearm fracture patients had the highest subsequent fracture rates (516/10,000 person-years in women and 380 in men). People born outside Europe and North America had the lowest rates (278/10,000 person-years in women and 286 in men). Compared to Norwegian-born individuals, the hazard ratios (HRs) of subsequent fracture in individuals from Europe and North American were 0.93 (95% CI 0.88-0.98) in women and 0.85 (95% CI 0.79-0.92) in men. The corresponding HRs in individuals from other countries were 0.76 (95% CI 0.70-0.84) in women and 0.82 (95% CI 0.74-0.92) in men. CONCLUSION: Individuals born outside Norway had a lower subsequent fracture risk than Norwegian-born individuals; however, subsequent fracture risk increased with age in all groups. Our results indicate that secondary fracture prevention should be recommended regardless of region of origin.

[Comparative study of short-term effectiveness of three surgical methods for ulnar styloid base fracture complicated with triangular fibrocartilage complex injury].

Objective: To compare the short-term effectiveness of arthroscopic suture of triangular fibrocartilage complex (TFCC), arthroscopic suture of TFCC combined with open reduction and internal fixation, and simple open reduction and internal fixation in the treatment of distal radius fractures combined with ulnar styloid base fractures and TFCC injury. Methods: A clinical data of 97 patients with distal radius fractures combined with ulnar styloid base fracture and TFCC injury, who were admitted between September 2019 and September 2022 and met the selective criteria, was retrospectively analyzed. After reduction and internal fixation of distal radius fractures, 37 cases underwent arthroscopic suture of TFCC (TFCC group), 31 cases underwent arthroscopic suture of TFCC combined with open reduction and internal fixation of ulnar styloid base fractures (combination group), and 29 cases underwent simple open reduction and internal fixation of ulnar styloid base fractures (internal fixation group). There was no significant difference in baseline data between groups ( P>0.05), such as gender, age, injury side, time from injury to operation, and preoperative radius height, palm inclination, ulnar deviation, grip strength, wrist range of motion (ROM) in rotation, ulnar-radial deviation, and flexion-extension. The differences (change value) in radius height, metacarpal inclination angle, ulnar deviation angle, grip strength, and wrist ROM in rotation, ulnar-radial deviation, and flexion-extension between preoperative and 12 months after operation in 3 groups were compared. The effectiveness was evaluated according to the modified Gartland-Werley score at 12 months after operation. Results: All incisions healed by first intention. All patients were followed up 12-18 months (mean, 14 months). X-ray films showed that there were 4 patients with non-union of ulnar styloid base fracture in TFCC group, and the remaining patients had fracture healing at 3 months after operation. The radius height, palm inclination, and ulnar deviation of 3 groups at 12 months after operation were significantly better than those before operation ( P<0.05); however, the differences in the change values of the above indexes between groups was not significant ( P>0.05). At 12 months after operation, the change values of wrist ROM in rotation, ulnar-radial deviation, and flexion-extension in the TFCC group and the combination group were significantly greater than those in the internal fixation group ( P<0.05), and there was no significant difference between the TFCC group and the combination group ( P>0.05). The change values of grip strength was significantly greater in the combination group than in the internal fixation group ( P<0.05); there was no significant difference between the other groups ( P>0.05). The excellent and good rates according to the modified Gartland-Werley score were 91.89% (34/37), 93.54% (29/31), and 72.41% (21/29) in the TFCC group, the combination group, and the internal fixation group, respectively. The excellent and good rates of the TFCC group and the combination group were significantly higher than that of the internal fixation group ( P<0.05); there was no significant difference between the TFCC group and the combination group ( P>0.05). Conclusion: For ulnar styloid base fractures with TFCC injury, compared with simple open reduction and internal fixation, arthroscopic suture of TFCC or suture TFCC combined with internal fixation treatment are both beneficial for wrist function recovery, and their short-term effectiveness are similar. Therefore, arthroscopic suture of TFCC may be a better choice.

[Impact of buried versus exposed flexible intramedullary nails osteosynthesis on pediatric forearm fractures]. / Impacto de los clavos intramedulares flexibles frente a los expuestos para osteosíntesis en fracturas pediátricas de antebrazo.

In elastic stable intramedullary nailing (ESIN), there are different opinions among surgeons on whether to leave the nail buried in the same arm or to leave it exposed. OBJECTIVE: To determine the risk of re-fracture in patients with a nail buried directly into the amr or left exposed as a treatment for forearm fractures, and to investigate postoperative complications. PATIENTS AND METHOD: The study included 113 pediatric patients with a forearm fracture of both diaphyses. Two groups were formed according to whether the nail was buried (Group B, n: 53) in the same arm or left exposed (Group E, n: 60). Data on the number of open reductions, the time to nail removal, the anesthesia type used for its removal, the number of re-fractures, skin infection, and nail entry site irritation were analyzed. RESULTS: The mean union times between the groups were not significantly different (P = 0.371). The mean time of nail removal in group B (16.02 ± 1.29 weeks) was significantly longer than that of group E (6.65 ± 0.95 weeks) (P < 0.001). Open reduction rates were similar between groups (P = 0.401). The general anesthesia rate for nail removal in group B (77.4%) was significantly higher than group E (11.7%) (P < 0.001). The re-fracture rate was higher in patients who underwent open reduction in both groups (P < 0.001). CONCLUSION: The results of this study demonstrated that, despite the increased infection rate, leaving the nail exposed did not increase the re-fracture rate, which was associated with open reduction.

Displaced sigmoid notch fracture and higher patient age are associated with distal radioulnar joint subluxation.

Background/aim: Distal radius fractures (DRFs) are frequently associated with distal radioulnar joint (DRUJ) instability. The purpose of this study is to evaluate the effect of the sigmoid notch and ulna styloid fracture types on DRUJ subluxation following closed reduction and casting of DRFs via calculating radioulnar ratio (RUR) on postreduction computed tomography (CT) images. Materials and methods: In our study, postreduction CT images of 202 patients with distal radius fractures were evaluated retrospectively. CT images were evaluated for RUR, sigmoid notch fracture, and ulna styloid types. Sigmoid notch fractures were classified as nondisplaced in the sigmoid notch fractures (NDS) and displaced sigmoid notch (DS) fractures; ulna styloid fractures were grouped as the proximal half ulna styloid (PHUS) and distal half ulna styloid (DHUS) fractures. Results: The mean age of Rozental type 3b (62.8 years) was significantly higher among others. The mean RUR value was significantly higher in Rozental type 3a in compared to type 1a and type 2 fractures. PHUS fractures were more common with DS fractures than DHUS fractures. Conclusion: DS fractures and higher patient age are associated with DRUJ subluxation on postreduction CT images following DRFs. DS fractures are seen more commonly with PHUS fractures than DHUS. Patients with PHUS should be carefully assessed for sigmoid notch fractures and DRUJ congruency. These findings could be helpful for preoperative decision making in the treatment of DRFs.

A retrospective study of Monteggia fractures in 8 dogs and 1 cat.

Monteggia fractures (MFs) are proximal ulnar fractures with concurrent dislocation of the radial head. This retrospective study aims to report the clinical findings and discuss the treatments and outcomes in MFs cases of 9 cases. Previous medical records of the animals were reviewed for history, clinical features, radiographic findings and choice of treatment. Treatment follow-up was evaluated over the telephone by discussion with the owners. Six animals included in the study were presented 2 days after the initial trauma. Five dogs were presented after common road traffic accidents and two after unknown traumas. All dogs had type I MFs, while the cat had a type III MF. Radiographical findings showed that six animals had extra-articular ulnar fractures, while three animals had intra-articular ulnar fractures. All animals were treated with open reduction of the ulna and internal fixation surgical methods. Six ulnar fractures were stabilized with intramedullary pin(s) with cerclage wire. The clinical outcome was assessed by the owners as full function in 3 dogs, acceptable function in 2 dogs and unacceptable function in 2 dogs with intraarticular ulnar fractures. The cat case was rated as full function. One dog died from a pulmonary fat embolism. The findings presented here provide some support that cerclage wire placement could be a satisfactory method for annular ligament reconstruction as a simple and economical treatment option. Also, to the authors' knowledge, this is the third report of MFs with intraarticular ulnar fractures. In this series, comminuted, intraarticular fractures were related to major postoperative complications.

Determinants of non-union after standard plate fixation for combined radial and ulnar fractures in adults.

Treatment of mid-shaft fractures of both forearm bones in adults typically consists of individual plate fixation of each bone according to AO principles. The primary objective of this multicentre retrospective study was to identify predictive and prognostic factors of failed bone union after internal fixation with a standard plate in adults. 130 mid-shaft fractures of both forearms occurred in 92 men and 38 women, who had a mean age of 35.1 years were reviewed; 42 were open: 31 were Gustilo type I, 10 were type II and 1 was type III. All patients underwent ORIF using a direct approach over the supinator crest for the ulnar fracture and using an anterior approach at the level of the radial fracture by dynamic compression plate in 90 cases and a limited-contact dynamic compression plate in 40 cases, all with 3.5 mm diameter screws. The radiographs from all patients were reviewed after a minimum follow-up of 12 months: primary union of both forearm bones occurred in 121 of the 130 cases after a mean of 4.6 months (±2.6). 104 patients were reviewed clinically with a minimum follow-up of 12 months and a mean of 36 months (±21.7). According to Tscherne-Oestern classification, 79 % of patients had a very good outcome, 6 % had a good outcome, 10 % had a fair outcome and 5 % had a poor outcome Non-union occurred in 9 patients (one septic): 4 times at both fracture sites, 4 times at the ulna only and once at the radius only. The mean age was higher in the patients with non-union: 46.4 years versus 34.2 (P = 0.08). Smoking, alcoholism, associated head trauma, presence of pre-operative nerve deficit and open fracture did not appear to be risk factors for non-union. The type of plate used and the number of screws placed on either side of the fracture site had no effect on union. This patient series had a similar non-union rate to the one reported in other published studies, likely because the technical rules were followed. A lack of statistical power probably prevented us from identifying prognostic factors for bone union.

Highly extensile approach for comminuted ulna coronoid process fractures with mini-plate fixation: a case series of 31 patients.

BACKGROUND: For the treatment of coronoid process fractures, medial, lateral, anterior, anteromedial, and posterior approaches have been increasingly reported; however, there is no general consensus on the method of fixation of coronal fractures. Here, we present a highly-extensile minimally invasive approach to treat coronoid process fractures using a mini-plate that can achieve anatomic reduction, stable fixation, and anterior capsular repair. Further, the study aimed to determine the complication rate of the anterior minimally invasive approach and to evaluate functional and clinical patient-reported outcomes during follow-up. METHODS: Thirty-one patients diagnosed with coronoid fractures accompanied with a "terrible triad" or posteromedial rotational instability between April 2012 and October 2018 were included in the analysis. Anatomical reduction and mini-plate fixation of coronoid fractures were performed using an anterior minimally invasive approach. Patient-reported outcomes were evaluated using the Mayo Elbow Performance Index (MEPI) score, range of motion (ROM), and the visual analog score (VAS). The time of fracture healing and complications were recorded. RESULTS: The mean follow-up time was 26.7 months (range, 14-60 months). The average time to radiological union was 3.6 ± 1.3 months. During the follow-up period, the average elbow extension was 6.8 ± 2.9° while the average flexion was 129.6 ± 4.6°. According to Morrey's criteria, 26 (81%) elbows achieved a normal desired ROM. At the last follow-up, the mean MEPI score was 98 ± 3.3 points. There were no instances of elbow instability, elbow joint stiffness, subluxation or dislocation, infection, blood vessel complications, or nerve palsy. Overall, 10 elbows (31%) experienced heterotopic ossification. CONCLUSION: An anterior minimally invasive approach allows satisfactory fixation of coronoid fractures while reducing incision complications due to over-dissection of soft tissue injuries. In addition, this incision does not compromise the soft tissue stability of the elbow joint and allows the patient a more rapid return to rehabilitation exercises.

Comparative analysis of tension band wiring and hook plate fixation in ulnar styloid fractures: a focus on fracture type.

INTRODUCTION: Various surgical techniques for ulnar styloid fractures (USFs) fixation have recently been developed, the actual clinical outcomes have not been discussed in detail. This study aimed to compare the outcomes of tension band wiring (TBW) and hook plate fixation in the treatment of USFs and to explore effective management strategies for these fractures. MATERIALS AND METHODS: We retrospectively reviewed 109 patients with styloid process fractures from March 2016 to July 2020. Among them, patients aged 21-75 years who required surgical intervention for USFs with distal radioulnar joint (DRUJ) instability, with or without accompanying distal radius fracturs (DRFs), were included. The patients were treated with either TBW (group T) or hook plate fixation (group P). The fractures were classified into four types based on their location and complexity. Postoperative assessments were conducted using radiographic analysis to monitor fracture healing. Clinical evaluations, including range of motion (ROM), grip strength, and patient-reported outcomes using the disabilities of the arm, shoulder, and hand scores and the visual analog scale for pain, were performed, at multiple time points up to a year after surgery. Statistical analyses were conducted to compare outcomes across fracture types and treatment methods. RESULTS: Osseous union was achieved in 96% of the patients. Specifically, the time to union in types 3 and 4 fractures was significantly shorter in group P than in group T. Functionally, ROM assessments showed similar flexion-extension in both groups but better pronation-supination in group T. Grip strength and patient-reported outcomes did not show significant differences between the groups. CONCLUSIONS: TBW offers slight ROM benefits for type 2 USFs, whereas hook plate fixation provides superior stability for complex types 3 and 4 USFs. Despite the minimal differences in ROM, the enhanced advantages of the hook plate fixation make it the preferred choice for severe fractures, ensuring faster healing.

Pure varus posteromedial rotatory instability of the elbow: Radiographic findings, treatment, and outcomes.

INTRODUCTION: Although varus posteromedial rotatory instability (VPMRI) is a subtle elbow injury that involves anteromedial coronoid facet (AMCF) fracture and ligamentous injuries, treatment options and outcomes of VPMRI remains controversial. The aim of this study was to investigate radiographic findings, treatments, and outcomes of a large series of VPMRI. METHODS: We retrospectively reviewed 91 pure VPMRI cases with AMCF fracture (O'Driscoll classification anteromedial type) which were treated at 6 hospitals. Clinical and radiographic outcomes were investigated with a mean follow-up period of 46.8 months using the Mayo elbow performance score (MEPS), and the Quick Disabilities of the Arm, Shoulder and Hand (Quick-DASH) score, and serial plain radiographs. RESULTS: In AMCF fracture, there were 4 cases of subtype 1, 67 cases of subtype 2, and 20 cases of subtype 3. On MRI, complete tears of lateral collateral ligament and medial collateral ligament were observed in 83.1 % (59/71 cases) and 33.8 % (24/71 cases). Operative treatment was performed in 68 cases (74.7 %) including both side fixation in 40 cases (58.8 %), medial side fixation only in 17 cases (25.0 %), and lateral side fixation only in 11 cases (16.2 %). Nonoperative treatment was performed in 23 cases (25.3 %). The mean final MEPS and Quick-DASH scores were 93.7 and 7.9. The overall complication and reoperation rates were 22.0 % and 15.4 %. No significant differences regarding final clinical scores and range of motions were observed between the operative group and the nonoperative group, but significant differences were observed regarding number (p = 0.019) and displacement (p = 0.002) of coronoid fragment, and complication rate (p < 0.001) between the two groups. CONCLUSION: Depending on the pattern of coronoid fragment and the degree of ligamentous injuries, operative treatment of unstable VPMRI using various fixation techniques including coronoid fixation and ligament repair yielded satisfactory final clinical outcomes. However, surgeons should be aware of the high complication and reoperation rates after operative treatment. Stable VPMRI with AMCF fracture involving minimal displacement or small number of fragments can be treated nonoperatively.

Erythropoietin as promoter of engraftment for treatment of radius/ulnar non-union fracture in a dog: Case report.

Background: Fractures with large bone defects and non-unions are a great challenge for veterinary orthopaedists. In small dog breeds, this complication is commonly encountered in fractures of the radius and ulna due to poorer vascularisation of the distal antebrachium region. Case Description: A case of radius/ulnar non-union in a 1.5-year-old Pinscher occurring after trauma and two successive unsuccessful osteosyntheses is described. During the operative revision, after the removal of existing bone implants, the bone defect was filled with cortical autologous bone graft. Autocancellous bone mixed with erythropoietin was applied proximally and distally to the cortical autograft for stimulation of bone healing. The post-operative period was without complications. As early as the 9th post-operative week, the animal was able to bear weight on the limb, without signs of lameness, pain, and swelling. Radiologically, a very good bridging of the graft was observed. Fifteen weeks after the operative revision, the fracture was completely healed with excellent clinical outcome. Conclusion: The application of autogenous cortical bone graft and cancellous autograft mixed with erythropoietin demonstrated an excellent therapeutic effect and resulted in complete regeneration of the large bone defect over a 15-week period.

Is casting of displaced paediatric distal forearm fractures non-inferior to reduction under general anaesthesia? Study protocol for a pragmatic, randomized, controlled non-inferiority multicentre trial (the casting trial).

BACKGROUND: Treatment of displaced distal forearm fractures in children has traditionally been closed reduction and pin fixation, although they might heal and remodel without surgery with no functional impairment. No randomized controlled trials have been published comparing the patient-reported functional outcome following non-surgical or surgical treatment of displaced paediatric distal forearm fractures. METHODS: A multicentre non-inferiority randomized controlled trial. Children aged 4-10 years with a displaced distal forearm fracture will be offered inclusion, if the on-duty orthopaedic surgeon finds indication for surgical intervention. They will be allocated equally to non-surgical treatment (intervention) or surgical treatment of surgeon's choice (comparator). Follow-up will be 4 weeks and 3, 6, and 12 months. The primary outcome is the between-group difference in 12 months QuickDASH score. We will need a sample of 40 patients to show a 15-point difference with 80% power. DISCUSSION: The results of this trial may change our understanding of the healing potential of paediatric distal forearm fractures. If non-inferiority of non-surgical treatment is shown, the results may contribute to a reduction in future surgeries on children, who in turn can be treated without the risks and psychological burdens associated with surgery. TRIAL REGISTRATION: www. CLINICALTRIALS: gov (ID: NCT05736068). Date of registry: 17 February 2023.

Treatment of Ulnar Coronoid Process Fracture Using the Anterior Neurovascular Interval Approach: A Retrospective Clinical Study with Short- to Mid-term Follow-up.

OBJECTIVE: Numerous surgical techniques for addressing ulnar coronoid process fractures are available; however, a consensus on the optimal approach remains elusive. This study aimed to use the anterior neurovascular interval approach for the surgical management of ulnar coronoid process fractures and to evaluate its clinical outcomes over short- to mid-term follow-up. METHODS: This retrospective clinical study included 20 patients with ulnar coronoid process fractures who were treated using the anterior neurovascular interval approach between January 2018 and December 2022. Participants comprised 16 males and four females, aged between 20 and 64 years (mean, 34.3 ± 12.44 years). Clinical and radiological evaluations were based on elbow joint range of motion (ROM), Visual analogue scale (VAS), and Mayo elbow performance score (MEPS). A paired t-test was used to compare the pre-operative and final follow-up VAS and MEPS scores. RESULTS: The follow-up duration for all patients was at least 12 months (average, 12.65 ± 1.60 months). At the final follow-up, measurements of elbow ROM included a mean extension of 2.85 ± 3.17°, mean flexion of 135 ± 7.25°, mean pronation of 86.4 ± 4.56°, and mean supination of 84.85 ± 5.54°. All participants reached their target MEPS, with an average score of 97.25 ± 4.72 points, and the final mean VAS score was 0.2 ± 0.52 points. The VAS score was significantly lower and MEPS score was higher at the final follow-up than those before surgery (p < 0.05). Throughout the follow-up period, all the fractures united, and the stability of the affected elbows was satisfactory. CONCLUSION: Employing the anterior neurovascular interval approach for open reduction and internal fixation to manage coronoid process fractures effectively facilitates anatomical restoration and robust fixation of ulnar coronoid process fractures.

The effect of Ding's screws and tension band wiring for treatment of olecranon fractures: a biomechanical study.

Although tension band wiring (TBW) is popular and recommended by the AO group, the high rate of complications such as skin irritation and migration of the K-wires cannot be ignored. Ding's screw tension band wiring (DSTBW) is a new TBW technique that has shown positive results in the treatment of other fracture types. The objective of this study was to evaluate the stability of DSTBW in the treatment of olecranon fractures by biomechanical testing. We conducted a Synbone biomechanical model by using three fixation methods: DSTBW, intramedullary screw and tension band wiring (IM-TBW), and K-wire TBW, were simulated to fix the olecranon fractures. We compared the mechanical stability of DSTBW, IM-TBW, and TBW in the Mayo Type IIA olecranon fracture Synbone model using a single cycle loading to failure protocol or pullout force. During biomechanical testing, the average fracture gap measurements were recorded at varying flexion angles in three different groups: TBW, IM-TBW, and DSTBW. The TBW group exhibited measurements of 0.982 mm, 0.380 mm, 0.613 mm, and 1.285 mm at flexion angles of 0°, 30°, 60°, and 90° respectively. The IM-TBW group displayed average fracture gap measurements of 0.953 mm, 0.366 mm, 0.588 mm, and 1.240 mm at each of the corresponding flexion angles. The DSTBW group showed average fracture gap measurements of 0.933 mm, 0.358 mm, 0.543 mm, and 1.106 mm at the same flexion angles. No specimen failed in each group during the cyclic loading phase. Compared with the IM-TBW and TBW groups, the DSTBW group showed significant differences in 60° and 90° flexion angles. The mean maximum failure load was 1229.1 ± 110.0 N in the DSTBW group, 990.3 ± 40.7 N in the IM-TBW group, and 833.1 ± 68.7 N in the TBW group. There was significant difference between each groups (p < 0.001).The average maximum pullout strength for TBW was measured at 57.6 ± 5.1 N, 480.3 ± 39.5 N for IM-TBW, and 1324.0 ± 43.8 N for DSTBW. The difference between maximum pullout strength of both methods was significant to p < 0.0001. DSTBW fixation provides more stability than IM-TBW and TBW fixation models for olecranon fractures.

Comparison of reamer irrigator aspirator (RIA) suspension versus bone marrow aspirate concentrate (BMC) for percutaneous treatment of long bone nonunions-A preclinical canine model.

OBJECTIVE: To compare the bone healing effects of percutaneously delivered bone marrow aspirate concentrate (BMC) versus reamer irrigator aspirator (RIA) suspension in a validated preclinical canine ulnar nonunion model. We hypothesized that BMC would be superior to RIA in inducing bone formation across a nonunion site after percutaneous application. The null hypothesis was that BMC and RIA would be equivalent. METHODS: A bilateral ulnar nonunion model (n= 6; 3 matched pairs) was created. Eight weeks after segmental ulnar ostectomy, RIA from the ipsilateral femur and BMC from the proximal humerus were harvested and percutaneously administered into either the left or right ulnar defect. The same volume (3 ml) of RIA suspension and BMC were applied on each side. Eight weeks after treatment, the dogs were euthanized, and the nonunions were evaluated using radiographic, biomechanical, and histologic assessments. RESULTS: All dogs survived for the intended study duration, formed radiographic nonunions 8 weeks after segmental ulnar ostectomy, and underwent the assigned percutaneous treatment. Radiographic and macroscopic assessments of bone healing at the defect sites revealed superior bridging-callous formation in BMC-treated nonunions. Histologic analyses revealed greater amount of bony bridging and callous formation in the BMC group. Biomechanical testing of the treated nonunions did not reveal any significant differences. CONCLUSION: Bone marrow aspirate concentrate (BMC) had important advantages over Reamer Irrigator Aspirator (RIA) suspension for percutaneous augmentation of bone healing in a validated preclinical canine ulnar nonunion model based on clinically relevant radiographic and histologic measures of bone formation.

Diagnosis and Treatment of Varus Posteromedial Rotational Instability of the Elbow Joint in Children: Re-Understanding of the Injury Mechanism Associated With Coronoid Process Fractures.

PURPOSE: To investigate the injury mechanism, diagnosis, and treatment of varus-posteromedial rotational instability of the elbow joint in children. METHODS: According to the diagnostic criteria of varus posteromedial rotational instability of elbow joint, 16 children with coronoid process fractures treated in our department from July 2013 to July 2017 were re-evaluated. There were 14 males and 2 females, aged 7 to 14 years, with an average age of 11.6 years. Eight cases on left and 8 cases on right side. An associated elbow dislocation occurred in 8 of 16 cases. Nine patients were treated with a lateral soft tissue repair only. In 7 other patients in addition to the lateral soft tissue repair, the coronoid process fractures were treated with open reduction and fixation. At the last clinical follow-up, each elbow joint range of motion was recorded, radiographs were obtained, and functional performance was evaluated by the Mayo elbow performance score (MEPS). RESULTS: The average follow-up time was 81.9 months for the 9 patients treated with lateral elbow soft tissue repair. At the last follow-up, 2 of the patients had MEPS scores as excellent, 1 was good, and 6 were rated as moderate or poor. Four patients had a cubitus varus deformity. The average follow-up time was 30.3 months for the 7 patients treated with both soft tissue repair and coronoid fracture stabilization. The elbow joint MEPS scores for each of these 7 patients was excellent at the last follow-up, and no complications such as cubitus varus occurred. CONCLUSION: The results of the study suggest that children could also develop elbow varus-posterior medial rotational instability injuries under the same mechanism. Although the morbidity rate is low, due to insufficient understanding of the injury mechanism, it is prone to missed diagnosis, misdiagnosis, and delayed treatment, resulting in severe complications such as elbow instability, dislocation, traumatic arthritis, and elbow stiffness. On the contrary, according to the treatment principle of the posterior medial rotational instability of the elbow joint in adult, while the lateral repair is carried out, strong and effective reduction and fixation of the coronoid process fractures are adopted, it is expected that such children with rare elbow injuries can obtain excellent treatment outcomes.