Osseous Union Research Articles

Increased rate of pseudarthrosis in the anterior intersegmental gap after mandibular reconstruction with fibula free flaps: a volumetric analysis.

Pseudarthrosis after mandibular reconstruction leads to chronic overload of the osteosynthesis and impedes dental rehabilitation. This study evaluates the impact of gap site on osseous union in mandible reconstruction using a new volumetric analysis method with repeated cone-beam computed tomography (CBCT). The degree of bone regeneration was evaluated in 16 patients after mandible reconstruction with a fibula free flap and patient-specific reconstruction plates. Percentual bone volume and width changes in intersegmental gaps were retrospectively analyzed using a baseline CBCT in comparison to a follow-up CBCT. Patients' characteristics, plate-related complications, and gap sites (anterior/posterior) were analyzed. Detailed assessments of both gap sites (buccal/lingual/superior/inferior) were additionally performed. Intersegmental gap width (p = 0.002) and site (p < 0.001) significantly influence bone volume change over two consecutive CBCTs. An initial larger gap width resulted in a lower bone volume change. In addition, anterior gaps showed significantly less bone volume changes. Initial gap width was larger at posterior segmental gaps (2.97 vs 1.65 mm, p = 0.017). A methodology framework has been developed that allows to quantify pseuarthrosis in reconstructed mandibles using CBCT imaging. The study identifies the anterior segmental gap as a further risk factor for pseudarthrosis in reconstructions with CAD/CAM reconstruction plates. Future research should evaluate whether this outcome is related to the biomechanics induced at this site.

The Impact of Smoking on Delayed Osseous Union After Arthrodesis Procedures in the Hand and Wrist

The purpose of this study was to evaluate the relationship between smoking and delayed radiographic union after hand and wrist arthrodesis procedures. We hypothesized that smoking would be associated with a higher rate of delayed union. All cases of hand or wrist arthrodesis procedures in patients aged ≥18 years from 2006 to 2020 were identified. Cases were included if they had >90 days of radiographic follow-up or evidence of union before 90 days. Baseline demographics were recorded for each case including smoking status at the time of surgery. Complications were recorded and all postoperative radiographs were reviewed to assess for evidence of delayed union (defined as lack of osseous union by 90 days after surgery). We compared active smokers and nonsmokers and performed a logistic regression analysis to estimate the odds of experiencing a delayed radiographic union. A total of 309 arthrodesis cases were included and 24% were active smokers. Overall, radiographic evidence of a delayed union was found in 17% of cases. Smokers were significantly more likely to have a delayed union compared with nonsmokers (27% vs 14%). Results of the adjusted logistic regression analysis demonstrated that there was a significantly increased odds of experiencing a delayed union for patients who were active smokers compared with nonsmokers (odds ratio, 2.20; 95% confidence interval, 1.09-4.43). In addition, the rate of symptomatic nonunion requiring reoperation was higher in smokers (15%) compared with nonsmokers (6%). Smoking was associated with increased odds of delayed radiographic union in patients undergoing hand and wrist arthrodesis procedures. Patients should be counseled appropriately on the risks of smoking on bone healing and encouraged to abstain from nicotine use in the perioperative period. Prognostic II.

Analysis of treatment effect with teriparatide on device-related vertebral osteopenia after lumbar spinal interbody fusion using Hounsfield unit values: A retrospective cohort study.

The aim of the present study was to investigate the effect of teriparatide on device-related vertebral osteopenia after single lumbar spinal interbody fusion and compare osteopenia in fused and nonfused spinal segments using Hounsfield unit (HU) values. The present study was a retrospective cohort study. We reviewed 68 consecutive patients (28 men and 40 women) who underwent single-segment (L4-5) transforaminal lumbar interbody fusion with cage and pedicle screw fixation. The patients were divided into 2 groups according to whether they were treated with teriparatide (teriparatide and nonmedication groups). The primary outcome measure was HU values measured on computed tomography images from each L1 to S1 vertebral body12-month postoperatively. Secondary outcome measures were femoral neck bone mineral density (BMD), T-score, osseous union, and clinical outcomes using the Japanese Orthopedic Association scoring system 12-month postoperatively. There were significant decreases in HU values of lumbar vertebral bodies at all levels and BMD and T-score values obtained using dual-energy X-ray absorptiometry of the femur between preoperative and postoperative 12-month computed tomography in the nonmedication group (P < .05). On the other hand, there were no significant differences between properative and postoperative 12-month HU values of each lumbar vertebral body and BMD values of the femur in the teriparatide group. Osseous fusion scores in the teriparatide group were significantly better than those in the nonmedication group. There were no significant differences in postoperative Japanese Orthopedic Association scores between the 2 groups. Administration of teriparatide during the perioperative period may prevent bone loss associated with spinal fusion surgery.

A new attempt to treat coronal plane fractures of the elbow joint with salvage via an anterior approach

BackgroundExisting approaches for treating elbow fractures include lateral, medial, anterior and posterior approaches, though the anterior approach is often not chosen by surgeons to avoid damage to important nerves and blood vessels. However, the anterior approach has unique advantages. The purpose of this study was to report outcomes of 38 patients with coronal plane elbow fractures treated through the anterior approach.MethodsWe retrospectively analyzed 38 cases of coronal plane elbow fracture treated through an anterior approach at our institution between March 2015 and July 2019. The length of the surgical incision, operation time, and postoperative complications were recorded. The range of flexion, extension, and rotation of the affected elbow and the healthy elbow were collected at follow-up. Functional outcomes were evaluated using the Mayo Elbow Function Score (MEPS).ResultsAll 38 patients were followed up for a mean of 21.26 months (range 12–36 months). Intraoperatively, the mean surgical incision length was 8 ± 2 cm and the mean operative time was 123 ± 59 min. At the final follow-up, solid osseous union was confirmed for all coronal plane elbow fractures. The mean elbow flexion arc was 129 ± 7°, and the extension arc was 9 ± 6°. The mean pronation arc was 83 ± 3°, and the supination arc was 80 ± 3°. The mean MEPS was 90 ± 8 points, with 18 excellent cases and 20 cases of excellent and good results, respectively. In 31 cases, there was no significant difference in elbow extension, flexion, or pronation between the single-fracture and healthy elbows (P > 0.05), though the arc of supination was slightly worse than that of the healthy elbow (P < 0.05). VAS pain scores before the operation, at three months after the operation, and during follow-up were compared, and pain was significantly reduced after treatment (P < 0.05). Two patients experienced transient postoperative median nerve paralysis, from which they recovered within three months. One patient had mild heterotopic ossification and was not treated because it did not affect the function of the elbow joint. All patients returned to work and were satisfied with the treatment.ConclusionThe anterior approach has the benefits of simplicity, safety, minimal invasiveness, excellent exposure, and satisfactory prognosis for coronal plane elbow fracture.

Paper 41: Suture-Bridge Fixation of Osteochondral Fractures and Osteochondritis Dissecans in the Knee: Excellent Rates of Early Lesion Stability and Osseous Union

Objectives:Preservation of articular cartilage in the setting of acute or chronic injury in the knee is paramount for long-term joint health. Achieving osseous union, minimizing implant related injury, and eliminating the need for reoperation for osteochondral fracture lesions (OCL) and osteochondritis dissecans (OCD) remain a challenge for the orthopedic surgeon. To evaluate osseous and chondral integration following a suture and non-metallic anchor (suture-bridge) construct utilizing magnetic resonance imaging (MRI). A secondary purpose was to assess the outcomes and short-term complications of suture bridge fixation of OCL and OCD in the knee.Methods:Consecutive patients (n=39, 41 knees) treated within a single academic sports medicine institution who underwent suture-bridge fixation of an OCL or OCD of the knee from initiation of the technique in 10/2019 through 03/2021 were reviewed with IRB approval. The suture-bridge technique employed 1.5 or2.9mm bioabsorbable knotless anchors (avg n= 3.93; 3-6) placed on the outside margins of the lesion with multiple strands (2-8) of hand-tensioned absorbable (87.5%; #0 or #1Vicryl) or non-absorbable (2-0 braided polyester) bridging suture. A minimum of six months follow up to assess bony union was required for inclusion, resulting in 40 knees in 38 patients available for study. Demographics, pre-operative MRI lesion characteristics, including lesion type (OCL vs OCD), presence of bone in within the fragment, size, and location, were documented. Healing was assessed by radiographs and MRI, with MRI obtained on all OCDs and any chondral-only OCL lesions. MRI was available on 33/40 (82.5%) knees within one year of surgery and was rated for lesion healing: Full Union = 100% cancellous or cancellous-chondral lesion continuity, Stable Union = >50% continuity with some fibrous tissue present, Un-united = < 50% continuity and extensive fibrous signal or fluid below the lesion. Complications, and rates and timing of return to sport (RTS) were evaluated. For assessment of early pain and functional improvement in the setting of isolated osteochondral treatment (without confounding concurrent patellar instability, or other treatment in conjunction with OCL), KOOS patient reported outcomes were analyzed in the OCD cohort at 6 and 12 months.Results:33 (82.5%) of all lesions demonstrated Full Union and no lesions failed treatment. MRI assessment of healing (5.8 months; 3-12 months) demonstrated 9 (64.3%) OCDs with Full union, 5 (35.7%) OCDs with Stable union, and none un-united (Figure 1); while OCLs demonstrated 17 (89.5%) with Full union, 2 (10.5%) with Stable union, and none un-united. (Figure 2) All 7 bony OCL without an MRI demonstrated radiographic union. 30 (75%) lesions returned to sports at an average of 6.5 months (3.8-10.2). KOOS Daily Living, Pain, Quality of Life, and Symptom scores all demonstrated significant improvement from baseline at 6months and 1 year. (Table 2). There were 2 (5%) complications consisting of re-operation for marginal chondroplasty on otherwise stable lesions, and no re-operations for failure or revision of the suture-bridge construct.Conclusions:In this series of OCL and OCD of the knee, suture-bridge fixation demonstrates excellent rates of MRI and radiographic union and good early outcomes with minimal short-term complications. This technique may be utilized for lesion salvage as preferred over loose body removal and marrow-stimulation and may have significant benefits in comparison to metallic and non-metallic screw/tack constructs in the treatment of these challenging lesions. Longer term follow-up and investigation is warranted.UPLOAD-https://planion-client-files.s3.amazonaws.com/AOSSM/blobs/96288f30-99be-431a-9937-0218d3245043/1/Suture_Bridge_AOSSMFinalfigures.docx

Congenital Atlanto-Occipital Fusion and its Effect on the Myodural Bridge: A Case Report Utilizing the P45 Plastination Technique

The atlanto-occipital joint is composed of the superior fossa of the lateral masses of the atlas (C1) and the occipital condyles. Congenital Atlanto-occipital fusion (AOF) involves the osseous union of the base of the occiput (C0) and the atlas (C1). AOF or atlas occipitalization/assimilation represents a craniovertebral junction malformation (CVJM) which can be accompanied by other cranial or spinal malformations. AOF may be asymptomatic or patients may experience symptoms from neural compression as well as limited neck movement. The myodural bridge (MDB) complex is a dense fibrous structure that connects the suboccipital muscular and its related facia to the cervical spinal dura mater, passing through both the posterior atlanto-occipital and atlanto-axial interspaces. It is not known if atlas occipitilization can induce structural changes in the MDB complex and its associated suboccipital musculature. The suboccipital region of a cadaveric head and neck specimen from an 87-year-old Chinese male having a congenital AOF malformation with resultant changes to the MDB complex was observed. After being treated with the P45 plastination method, multiple slices obtained from the cadaveric head and neck specimen were examined with special attention paid to the suboccipital region and the CVJM. Congenital atlanto-occipital fusion malformations are defined as partial or complete fusion of the base of the occiput (C0) with the atlas (C1). In the present case of CVJM, unilateral fusion of the left occipital condyle with the left lateral mass of C1 was observed, as well as posterior central fusion of the posterior margin of the foramen magnum with the posterior arch of C1. Also noted was a unilateral variation of the course of the vertebral artery due to the narrowed posterior atlanto-occipital interspace. Surprisingly, complete agenesis of the rectus capitis posterior minor (RCPmi) and the obliques capitis superior (OCS) muscles was also observed in the plastinated slices. Interestingly, the MDB, which normally originates in part from the RCPmi muscle, was observed to originate from a superior bifurcation within an aspect of the nuchal ligament. Therefore, the observed changes involving the MDB complex appear to be an effective compensation to the suboccipital malformations.

Osseous Union after Mandible Reconstruction with Fibula Free Flap Using Manually Bent Plates vs. Patient-Specific Implants: A Retrospective Analysis of 89 Patients.

The aim of this monocentric, retrospective clinical study was to evaluate the status of osseous union in uni- and poly-segmental mandible reconstructions regarding conventional angle-stable manually bent osteosynthesis plates (Unilock 2.0 mm) versus titan laser-melted PSI patient-specific implant’s (PSI). The clinical impact of PSI’s high stiffness fixation methods on bone healing and regeneration is still not well addressed. The special interest was in evaluating the ossification of junctions between mandible and fibula and between osteotomized fibula free flap (FFF) segments. Panoramic radiograph (OPT), computed tomography (CT) scans, or cone-beam CTs (CBCT) of patients who underwent successful FFF for mandible reconstruction from January 2005 to December 2020 were analyzed. A total number of 89 cases (28 females (31.5%), 61 males (68.5%), mean age 58.2 ± 11.3 years, range: 22.8–82.7 years) fulfilled the chosen inclusion criteria for analysis (conventional: n = 44 vs. PSI: n = 45). The present study found an overall incomplete ossification (IOU) rate of 24.7% (conventional: 13.6% vs. PSI: 35.6%; p = 0.017) for mandible to fibula and intersegmental junctions. Between osteotomized FFF segments, an IOU rate of 16% was found in the PSI-group, while no IOU was recorded in the conventional group (p = 0.015). Significant differences were registered for IOU rates in poly-segmental (p = 0.041), and lateral (p = 0.016) mandibular reconstructions when PSI was used. Multivariate logistic regression analysis identified plate exposure and type of plate used as independent risk factors for IOU. Previous or adjuvant radiotherapy did not impact incomplete osseous union in the evaluated study sample. PSI is more rigid than bent mini-plates and shields functional mechanical stimuli, and is the main reason for increasing the rate of incomplete ossification. To enhance the functional stimulus for ossification it has to be discussed if patient-specific implants can be designed to be thinner, and should be divided into segmental plates. This directs chewing forces through the bone and improves physiological bone remodeling.

Suture-Bridge Fixation of Osteochondrial Fractures and Osteochonritis Dissecans in the Adolescent Knee: Mir Assement of Healing

Background:Preservation of articular cartilage in the setting of adolescent knee injury is paramount for long-term joint health. Achieving osseous union, minimizing implant related injury, and eliminating need for reoperation for osteochondral fracture lesions (OCL) and osteochondritis dissecans (OCD) remain a challenge for orthopedic surgeons.Hypothesis/Purpose:To evaluate MRI appearance of osseous and chondral integration following suture bridge construct. Secondarily, to assess short-term complications and outcomes of suture bridge fixation of OCL and OCD in adolescent knees.Methods:Consecutive patients (n=41) treated within a pediatric sports medicine institution who underwent suture-bridge knee fixation of an OCL or OCD from 10/2019-03/2021 were reviewed. MRI within 6 months of surgery was required. Analysis included demographics, pre-operative MRI lesion characteristics, surgical technique, suture type, Postoperative MRIs for lesion healing (Full Union: 100% cancellous/cancellous-chondral lesion continuity, Stable Union: >50% continuity with some fibrous tissue present, Un-united: < 50% continuity and extensive fibrous signal or fluid below the lesion), complications, rates and timing of return-to-sport (RTS), and short-term patient-reported outcomes (Pedi-IKDC, Pedi-FABS, KOOS Symptoms, PROMIS® ).Results:22 knees (20 patients) included 11 OCL and 10 OCD (Table 1). Lesion characteristics: OCL-mean size=248.2(140-459)mm2, mean major length=17.3(12-27)mm, osteochondral= 10(83%), all chondral= 2(17%); OCD-mean size =374.4(130-780)mm2, mean major length=19.3(10-29)mm, progeny bone present =7(70%). 91%(20/22) were treated via mini-arthrotomy, and 86%(19/22) of constructs were absorbable suture. At MRI follow up (6.7 months, 3.0-21.1), OCLs demonstrated 91.7% Full Union, 8.3% Stable Union, 0% Un-united; OCDs demonstrated 50% Full Union, 50% Stable Union, 0% Un-united. At average of 6.4 months, 19(86%) knees had RTS. Pedi-FABS demonstrated a return to similar level of activity and Pedi-IKDC indicated functional improvement in 80% on average 9.6 months post-operatively (Table 2). There were 2 (9.1%) complications (1. repeat arthroscopy for chondroplasty and marrow stimulation for 20% distal margin instability of patellar OCL secondary to patellar instability, 2. Second surgery for patellar stabilization following trochlear OCD suture-bridge in the setting of trochlear dysplasia and no stabilization at primary procedure) and no re-operations needed for suture-bridge construct.Conclusion:In this series of knee OCLs and OCDs, suture-bridge fixation demonstrates excellent rates of healing based on MRI appearance and good early outcomes with minimal short-term complications. This technique may be used by surgeons to avoid loose body removal and marrow-stimulation, and have significant benefits in comparison to metallic and non-metallic screw/tack constructs in the treatment of these challenging lesions. Longer term follow-up and investigation is warranted.Table 1.Patient Demographics and Lesion LocationTable 2.Patient Reported Outcomes

Arthroscopic Reduction and Internal Fixation of an Osseous Bankart Lesion.

The current surgical video article outlines a technique for an osseous Bankart repair in a patient with a displaced fracture as well as substantial pain and instability. First, the amount of bone loss is measured on 3-dimensionally reconstructed computed tomography (CT) imaging, with the humeral head digitally subtracted2. The procedure is then performed arthroscopically with the patient in the lateral decubitus position. A diagnostic evaluation, beginning with posterior and anterior portal placement in the rotator interval, is completed to assess any rotator cuff injury and the extent of labral tearing and osseous displacement. Next, the bone fragment is elevated into its anatomical position. This fragment is then reduced with use of a double-row suture technique, followed by concomitant capsulolabral repair. Nonoperative treatment with a sling can be utilized as long as post-reduction CT scans reveal anteroposterior centering of the humeral head on the glenoid3. Rehabilitation can include active-assisted and passive glenohumeral mobilization, as well as daily pendulum exercises and physiotherapy. Osseous Bankart repair has been shown to effectively improve patient-reported outcomes and normalize glenoid morphology1,3,4. Failure to recognize and appropriately treat an osseous Bankart fracture may lead to osseous erosion caused by repetitive episodes of subluxations or dislocations, along with substantial pain and weakness5. Indications for arthroscopic Bankart repair include young, active patients with a reducible fracture fragment, an anterior glenoid deficit of >10%, and a history of failed nonoperative treatment3-8. Clinical outcomes following the osseous Bankart repair procedure have been shown to be highly successful, with high rates of return to sport, minimal reduction in range of motion, and restoration of shoulder function and stability4. Additionally, long-term follow-up has shown successful osseous union and normalization of glenoid anatomy1. Apply tension to sutures with a suture retriever before the PushLock anchors (Arthrex) are placed during fracture reduction.Utilize a trans-subscapularis portal for anchor placement medial to the fracture on the glenoid neck.Perform adjustable tensioning during labral repair with knotless all-suture anchors.Utilize a lateral distraction device with the patient in the lateral decubitus position to completely visualize the anteroinferior glenoid.Chronic onset and late intervention may cause difficulties in the reduction of the bone fragment.Suture management may be difficult, particularly for surgeons at an early stage of the learning curve.A defect that is wide (from medial to lateral) may be difficult to maneuver around and reduce. GH = glenohumeralGHL = glenohumeral ligamentPts = patientsPMH = previous medical historyFE = forward elevationER = external rotationIR = internal rotationABD = abductionEXT = external rotationXR = radiographic imagingMRI = magnetic resonance imagingCT = computed tomographyROM = range of motionFU = follow-upRTS = return to sportsRTPP = return to previous level of play.

The Cuistow: A Modified Arthroscopic Bristow Procedure for the Treatment of Recurrent Anterior Shoulder Instability.

Specific instruments have been designed to improve the safety and accuracy of the arthroscopic inlay Bristow procedure (Weigao, Shangdong, China). The posterior portal (A), superolateral portal (B), and 3 anterior portals (i.e., proximal [C], inferolateral [D], and inferomedial [E]) were utilized. General anesthesia and an interscalene block were administered with the patient in the beach-chair position. The surgical technique can be divided into 6 steps: (1) evaluation of the shoulder joint; (2) coracoid preparation, drilling, and osteotomy; (3) subscapularis splitting and labrum detachment; (4) glenoid preparation and drilling; (5) coracoid retrieval, trimming, transfer, and fixation; and (6) Bankart repair. Soft-tissue capsulolabral repairs or bone reconstruction procedures are commonly performed for the treatment of anterior glenohumeral instability2. The arthroscopic Bristow-Latarjet procedure is increasingly popular for the treatment of anterior shoulder instability with a substantial osseous defect of the glenoid3. Defects that are too large to be restored with the coracoid process can be treated with use of the Eden-Hybbinette procedure or a distal tibial allograft4,5. This procedure was inspired by the structure of mortise-tenon joints, resulting in a modified version of the Bristow-Latarjet technique in which the coracoid process is trimmed and placed into a trough (5 to 10 mm deep) in the glenoid neck. This procedure substantially increases the contact area between the fresh bone surface and the coracoid and glenoid neck. Another important advantage of this technique is that it can facilitate accurate positioning of the coracoid on the glenoid. This procedure resulted in a high rate of graft healing, excellent functional outcomes (Rowe and American Shoulder and Elbow Surgeons Shoulder scores), and a high rate of return to sport6. Currently, indications of this procedure are (1) participation in high-demand sports (i.e., collision and overhead) combined with the presence of a glenoid defect involving <25% of the glenoid, or (2) any glenoid defect involving 10% to 25% of the glenoid. Increased bone-contact area and accurate positioning of the graft helped to facilitate osseous union, with a union rate of 96.1% at 12 months postoperatively. The clinical outcomes were excellent, with a high rate of return to sport (87%) at a minimum of 3 years of follow-up6. When the coracoid is retrieved through portal D (the inferolateral portal), there is a risk of stretching the musculocutaneous nerve.Trimming the coracoid graft could lead to stretching of the graft and the surrounding soft tissue, resulting in overstretching of the musculocutaneous nerve.To minimize the risk of musculocutaneous nerve injury, (1) the graft should be gently retrieved through portal D, (2) the graft should be trimmed with caution without overstretching it and surrounding soft tissue, and (3) a cannula should be utilized when driving the screw to fix the graft in order to avoid the surrounding soft tissue. RHD = right-hand dominantMRA = magnetic resonance angiography3D-CT = 3-dimensional computed tomographyPDS = polydioxanone sutureMCN = musculocutaneous nerve.

Patient-Specific 3D-Printed Miniplates for Free Flap Fixation at the Mandible: A Feasibility Study.

BackgroundThis study was conducted to evaluate the feasibility, clinical outcomes, and accuracy of patient-specific 3D-printed miniplates for mandible reconstruction with fibula free flaps.MethodsA feasibility study was conducted with 8 patients. Following virtual planning, patient-specific 1.0 mm titanium non-locking miniplates were produced via laser selective melting. 3D-printed cutting and drilling guides were used for segmental mandible resection and flap harvesting. Flap fixation was performed with two 4-hole miniplates and 2.0 mm non-locking screws (screw length 7 mm) for each intersegmental gap. Clinical follow-up was at least 6 months. Preoperative and postoperative CT/cone beam CT data were used for 3D accuracy analysis and evaluation of bone healing. Plate-related complications were monitored clinically.ResultsPatient-specific miniplate fixation of all flaps was successfully conducted (4 mono-segmental, 4 dual-segmental) with high accuracy (3.64 ± 1.18 mm) between the virtual plan and postoperative result. No technical complications were encountered intraoperatively. Osseous union occurred in all intersegmental gaps (1 partial, 18 complete) after 10 ± 2 months. No material fracture, dislocation, or plate exposure was observed.ConclusionsBased on this pilot observational study including a limited number of patients, free flap fixation for mandibular reconstruction with patient-specific 3D-printed miniplates is feasible and associated with high accuracy, bone healing, and remote soft tissue complications.

357 Novel Osteoconductive, Bioresorbable Bone Adhesive Provides Superior Cranial Flap Fixation Strength and Reduced CSF Leak Potential in a Cadaver Model

INTRODUCTION: Plates and screws are the gold standard for cranial flap fixation. Unfortunately, hardware may be associated with loosening and migration. Osseous union of the fixated flap to the surrounding skull is typically incomplete. Furthermore, titanium plates and screws do not provide a watertight closure of the bone and cannot mitigate CSF leakage. METHODS: 64 craniotomies were performed in 16 cadavers by a single neurosurgeon. Frontal, pterional, parietal, and parieto-occipito-temporal flaps were created in each skull. The 64 bone flaps were fixated by 16 different neurosurgeons (4 flaps/surgeon). Each flap was secured with standard cranial plates and screws, then biomechanically tested using either quasi-static compression (1mm/min) or staircase impact (up to 60J impact energy at increments of 6J) to analyze mechanical strength. Next, the plates and screws were removed and the same bone flap was secured by the same neurosurgeon using a novel bone adhesive, Tetranite®(TN). The TN-secured flaps were then biomechanically tested in similar fashion. A subset of the TN-fixated flaps was subjected to hydrostatic fluid pressure (up to 40mm Hg at steps of 5mm Hg) to determine resistance to simulated CSF leakage prior to mechanical testing. RESULTS: TN fixation was approximately 41 times stiffer and 48 times stronger than metal fixation under quasi-static loading (stiffness 4216±1544N/mm and peak force 5456±1920N for TN vs. 103 ±81N/mm and 113±89N for metal hardware: n=32). At an impact energy of 6J, cranial flaps fixated using metal hardware migrated to a peak deflection 13 times greater than TN-fixated specimens; the residual plastic deformation was 30 times greater (peak elastic deflection 2.94± 0.81mm and plastic deflection of 1.69±0.93mm for metal hardware vs. 0.24±0.07mm and 0.06±0.04mm for TN; n=31). Of 16 TN-fixated specimens tested hydrostatically, none leaked under pressures up to 35mmHg held for 5 secs, and only 2 specimens leaked at 40mmHg. CONCLUSION: TN was biomechanically superior to standard cranial hardware for flap fixation. Additionally, TN acted to prevent fluid leakage. TN holds promise for improving cranial bone flap fixation biomechanically, cosmetically, and hydrostatically.

First Tarsometatarsal Joint Arthrodesis for Hallux Valgus With and Without Intermetatarsal Screw Fixation: A Comparison of Correction and Maintenance of Correction

Tarsometatarsal joint arthrodesis is a commonly accepted procedure for hallux valgus associated with severe deformity and first ray hypermobility or medial column instability. This study evaluates the correction of hallux valgus deformity and the maintenance of correction with and without the use of a stabilization screw between the first and second metatarsal bases. Through retrospective review of first tarsometatarsal joint arthrodesis within our institution we evaluated 63 patients. Twenty-seven patients did not have a first to second metatarsal base screw and were placed into the no screw cohort. Thirty-six patients did have a first to second metatarsal base screw and were placed into the screw cohort. This study population had an osseous union rate of 95%. Clinical and radiographic recurrence occurred in 5 of 63 patients (8%). At 1-y postop the measurements demonstrated that the screw cohort had an average intermetatarsal angle correction of 11.6 degrees while the no screw cohort had an average correction of 7.8 degrees. Additionally, at 1-y postop the screw cohort had greater maintenance of the intermetatarsal angle correction with an average change of 0.5 degrees compared to 2.3 degrees in the no screw cohort. We conclude that the addition of the stabilization screw improves the first tarsometatarsal joint arthrodesis construct resulting in a greater degree of realignment and maintenance of correction.

The Hoffa-like fracture of the tibial plateau: a clinical study.

Given the contrapositive link between the posterior tibial plateau and the femoral condyle and the similar injury cause, the fracture type should be the same as the well-known Hoffa fracture of the femoral condyle. This study aims to report a case series with Hoffa-like tibial plateau fractures to improve understanding. We analysed six consecutive patients presented with Hoffa-like tibial plateau fractures in our hospital between October 2014 and December 2020, a period in which 1924 tibial plateau fractures were treated. Patients' data on demographics, radiographs, surgical therapy, and assessment at a 12-month follow-up were retrieved. The incidence of Hoffa-like tibial plateau fractures was 0.31% (6/1924). This study included three men and three women, with a mean age of 45.8years. The injury mechanism was either a fall from a great height or a vehicle accident. On average, 7.5days after the injury, patients were surgically treated with open reduction and internal fixation (ORIF) with place/screws via a lateral or posteromedial approach. At 10 to 15weeks, all instances had osseous union on radiography. At 12-month follow-up, the HSS score of the operated knee ranged from 93 to 98 points (mean: 94.8), and Rasmussen radiograph score was from 15 to 18 (mean: 15.8). There were no intra-operative or post-operative problems. This Hoffa-like fracture of the tibial plateau is a rare condition; however, it can occur. Orthopaedic surgeons should pay attention to this neglected but actually familiar fracture type.

Outcomes Following Different Fixation Strategies of Neer Type IIB Distal Clavicle Fractures.

Multiple surgical techniques for fixation of Neer type IIB distal clavicle fractures have been described without consensus on optimal treatment. The purpose of this study is to compare functional and radiographic results with surgical management of Neer type IIB distal clavicle fractures at a single institution. Sixty-three patients with acute Neer type IIB fractures treated operatively were evaluated. Patients with a minimum of two year follow up were included. Functional scores included American Shoulder and Elbow Surgeons (ASES), Single Assessment Numeric Evaluation (SANE), Simple Shoulder Test (SST), and Likert patient satisfaction (1 to 5). Radiographs were assessed for osseous union and coracoclavicular (CC) distance. Thirty-eight patients met inclusion with a mean follow-up of 5.3 years. Patients were divided into five groups based on fixation technique: suture-only CC fixation (n=6), CC screw fixation only (n=3), open reduction internal fixation (ORIF) without CC fixation (n=8), hook plate fixation (n=4), and ORIF with suture CC reconstruction (n=17). Outcome scores for the entire cohort were 91.8 for ASES, 90.2 for SANE, and 10.8 for STT. Patients with hook plates had significantly lower SANE score (p=0.016), but no other significant differences in functional, satisfaction, or radiographic outcomes were found between groups. Sixteen patients (42.1%) required reoperation. Treatment of Neer type IIB fractures via suture- only fixation, plate-only fixation, or a combination of both demonstrated satisfactory mid to long term outcomes. While implant removal was more common in the CC screw and ORIF groups, no fixation technique proved functionally superior.

Studying the Feasibility of Postoperative Monitoring of Spinal Fusion Progress Using a Self-Powered Fowler-Nordheim Sensor-Data-Logger.

This study investigates the feasibility of using a new self-powered sensing and data logging system for postoperative monitoring of spinal fusion progress. The proposed diagnostic technology directly couples a piezoelectric transducer signal into a Fowler-Nordheim (FN) quantum tunneling-based synchronized dynamical system to record the mechanical usage of spinal fixation devices. The operation of the proposed implantable FN sensor-data-logger is completely self-powered by harvesting the energy from the micro-motion of the spine during the course of fusion. Bench-top testing is performed using corpectomy models to evaluate the performance of the proposed monitoring system. In order to simulate the spinal fusion process, different materials with gradually increasing elastic modulus are used to fill the intervertebral space gap. Besides, finite element models are developed to analyze the strains induced on the spinal rods during the applied cyclic loading. Data measured from the benchtop experiment is processed using an FN sensor-data-logger model to obtain time-evolution curves representing each spinal fusion state. This feasibility study shows that the obtained curves are viable tools to differentiate between conditions of osseous union and assess the effective fusion period.

Lunatocapitate and Triquetrohamate Arthrodeses for Degenerative Arthritis of the Wrist: A Midterm Follow-Up.

Degenerative arthritis of the wrist is a common condition often treated with 4 corner arthrodesis (FCA) or a partial wrist fusion. A number of limited intercarpal arthrodeses have been proposed for treatment of this condition. One technique, described by Wang and Bednar in 2012, involves fusion of the lunatocapitate and triquetrohamate joints. This study presents midterm follow-up of outcomes following this 2 column arthrodesis. From 2000 to present, patients who underwent lunatocapitate and triquetrohamate arthrodesis were evaluated. The original cohort from the 2012 study was reviewed, as well as any additional patients who since underwent this procedure. Only patients who had greater than 5 years of follow-up data were included. Outcomes included demographics, wrist range of motion, grip strength, complications, and radiographic evidence of union. Twenty-one cases were included in the final analysis. Mean follow-up was 8.75 years. Wrist extension and flexion were 58% and 90% of the unaffected side, respectively. Grip strength was 92% of the unaffected side. Osseous union was achieved in 95.2% of cases. Two cases underwent revision surgery, one for nonunion and one following a fall. Lunatocapitate and triquetrohamate arthrodesis offers a treatment for wrist arthritis that yields good clinical outcomes, low nonunion rates, and no conversions to total wrist arthrodesis, as shown by 5-year follow-up data. Limited intercarpal arthrodesis is an alternative to FCA, with the advantage of a smaller surgical footprint and simpler technique, while still providing excellent mid- to long-term outcomes.

Successful Nonsurgical Management of a Traumatic Dens Fracture in a Cat with Clinical and Radiographic Resolution

ABSTRACTAn adult domestic shorthair presented with obtundation, vestibular ataxia, head tilt, and visible evidence of facial injury following motor vehicle trauma. Plain radiographs and computed tomography imaging revealed a complete minimally displaced transverse fracture of the caudal aspect of the dens of the C2 vertebra and multiple minimally displaced cranial fractures. The dens fracture was managed with 8 wk of strict rest, followed by 4 wk of supervised activity at home. No external immobilization was performed. Neurological examinations at 8 days, 10 wk, and 9 mo following initial presentation were normal. Repeat radiographic and computed tomography examinations at 10 wk and 9 mo following the traumatic event demonstrated progressive and eventual complete osseous union of the fractured dens. To the authors’ knowledge, this is the first report of successful nonsurgical management of a traumatic dens fracture in an adult cat with documented radiographic and clinical resolution. This report suggests that nonsurgical management can be considered in such cats and that complete resolution with osseous union is feasible.

Strut Onlay Allograft in Revision Arthroplasty: Osseous Union and Clinical Outcome.

To evaluate the clinical outcome and the osseous union of strut onlay allografts (SOAs) used as adjunct in revision total joint arthroplasty (TJA). Patients that had previously undergone SOA augmentation were considered for inclusion. Patients were invited to provide information for the following: Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), EuroQol five dimension score (EQ-5D) and Parker mobility score. Osseous union rates between SOA and the host bone were determined by radiograph with the Emerson classification system. Bone mineral density was measured via quantitative computed tomography. Seventeen patients were identified, at a mean follow-up of 2.8 years. The median total WOMAC score was 22 [interquartile range (IQR)=21]. The median EQ-5D score was 0.887 (IQR=0.350) (time trade-off). The Parker Mobility Score was 8.0 (IQR=3.5). Emerson stages of radiographic graft to host union were 'rounding off' in one case, 'partial bridging' in three and 'complete bridging' in 13. Quantitative computed tomography showed an average bone mineral density of approximately 1,300 mg/cm3. From our findings, it is concluded that SOAs used in revision total joint arthroplasty provide promising results and are recommended for broader clinical use. A complete osseous union between host and graft bone was observed in the majority of cases.

Treatment of open and comminuted mid-distal tibial fractures by bilateral external fixation combined with limited-internal fixation.

Open and comminuted mid-distal fractures often result from high-energy trauma, and a concomitant poor blood supply often leads to skin necrosis, infection, and bone union. To circumvent such complications, we used limited-reduction and bilateral-external fixators to treat open and comminuted mid-distal tibial fractures with compromised soft tissue. A retrospective series of 34 patients who had open and comminuted mid-distal tibial fractures and treated by bilateral-external fixators with limited-internal fixation were analyzed. Patients were followed for 10-25 months (mean: 12 months) post-treatment and osseous union was achieved in each case. The average union time was 16.3 weeks. Based on the Johner- Wruhs criteria, the retrospective series consisted of 21 'excellent' cases, 8 'good' cases, 4 'fair' cases, and a 'poor' case. The total percentage of 'excellent' and 'good' cases of fracture recovery was 85.29%. Bilateral-external and limited-internal fixators pro- vided high bone union rate and excellent ankle-joint motion. Hence, it is an appropriate surgical approach for treating open and comminuted mid-distal tibial fractures with compromised soft tissue.