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Bone graft resorption following the Latarjet procedure has received considerable concern. Current methods quantifying bone graft resorption rely on two-dimensional (2D) CT-scans or three-dimensional (3D) techniques, which do not represent the whole graft volume/resorption (i.e., 2D assessment) or expose patients to additional radiation (i.e., 3D assessment) as this technique relies on early postoperative CT-scans. The aim of the present study was to develop and validate a patient-specific, CT-morphometric technique combining image registration with 3D CT-reconstruction to quantify bone graft resorption following the Latarjet procedure for recurrent anterior shoulder instability. Pre-operative and final follow-up CT-scans were segmented to digitally reconstruct 3D scapula geometries. A virtual Latarjet procedure was then conducted to model the timepoint-0 graft volume, which was compared with the final follow-up graft volume. Graft resorption at final follow-up was highly correlated to the 2D gold standard-technique by Zhu (Kendall tau coefficient = 0.73; p < 0.001). The new technique was also found to have excellent inter- and intra-rater reliability (ICC values, 0.931 and 0.991; both p < 0.001). The main finding of this study is that the technique presented is a valid and reliable method that provides the advantage of 3D-assessment of graft resorption at long-term follow-up without the need of an early postoperative CT-scan.

Background: Recurrent shoulder instability is a prevalent condition, with glenoid bone loss as a common cause. Arthroscopic repair using distal tibial allografts provides long-lasting treatment by restoring glenoid surface area and presumably avoids risks of sensitization against donor human leukocyte antigen (HLA). Two case studies have challenged this assumption, suggesting that small bone allografts are able to induce host adaptive immune responses to donor HLA. The incidence of small bone allograft HLA sensitization and its effects on resorption and patient outcomes are unclear. Purpose/Hypothesis: The purpose was to assess the rate of sensitization against donor HLA after distal tibial allograft procedures for shoulder instability due to glenoid bone loss and to find whether HLA sensitization negatively affects patient-reported and radiographic outcomes. We hypothesized that sensitized patients would have worse radiographic and self-reported outcomes compared with nonsensitized patients. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 71 patients with a mean age of 28.85 years (range, 13.58-61.31 years) were enrolled, with 58 patients submitting sufficient pre- and postoperative blood samples for HLA antibody testing. In patients who developed HLA antibodies postoperatively, donor HLA typing was used to confirm donor-specific sensitization. Pre- and postoperative computerized tomography scans (0.9 ± 0.8 years follow-up) were used to grade resorption based on the modified Zhu resorption grade classification (ie, grade 0 = no resorption; grade 1 = less than 25% resorption; grade 2 = between 25% and 50% resorption; and grade 3 = larger than 50% resorption). The Western Ontario Shoulder Instability Index outcome scores were obtained preoperatively and at regular postoperative appointments. Resorption and outcome data were compared between sensitized and nonsensitized patients using the Fisher exact test, independent 2-tailed Student t tests, and the Wilcoxon rank-sum test to determine the effect of HLA sensitization on radiographic and patient-reported outcomes. Results: A total of 7 (12.1%) patients with sufficient HLA samples were sensitized against donor HLA postoperatively. Sensitized patients did not have significantly higher rates of resorption (21.9% vs 14.3%, 21.9% vs 28.6%, 43.8% vs 28.6%, and 12.5% vs 28.6% for respective resorption grades 0-3; P = .67; α = .05). Self-reported outcomes were not statistically significant between sensitized and nonsensitized patients (24.9 ± 27.61 vs 40.16 ± 18.99; P = .37; α = .05) and did not differ significantly based on resorption grade (47.4 ± 0.0 vs 55.2 ± 18.8, 30.4 ± 15.8 vs 39.9 ± 20.9, 41.2 ± 0.0 vs 39.1 ± 13.1, and -24.9 ± 0 vs 24.4 ± 19.6 for resorption grades 0-3; P > .05; α = .05). Conclusion: Sensitization against donor HLA after small bone graft allografting was not previously considered but has been brought to light as a possibility. Aside from potential complications for future organ transplants, HLA sensitization does not introduce a risk for adverse outcomes or higher grades of resorption compared with nonsensitized patients after small bone allografting for shoulder instability.

Objective: The purpose of this case report was to present a method for the assessment of volumetric changes of bone blocks during healing and demonstrate its practicability by analysing the resorption of a preshaped allogeneic bone block used for the reconstruction of a complex maxillary defect. Materials and methods: CBCT-scans of a 19-year-old male treated with an allogeneic bone block were recorded pre-OP, post-OP, and following six months of healing. Graft shrinkage was assessed via two image matching tools, namely coDiagnostiX® and Slicer. A biopsy specimen was harvested along the implant canal at the time of implantation. Results: The osseous defect was successfully restored and advanced graft remodelling was found upon re-entry as confirmed by the histomorphometric and histologic analysis. The initial volumes of the graft determined via coDiagnostiX® and Slicer were 0.373 mL and 0.370 mL., respectively, while graft resorption after six months of healing was 0.011 mL (3.00%) and 0.016 mL (4.33%). Conclusions: The avoidance of bone harvesting and reduction of invasiveness display an important issue in dentoalveolar restorations. However, before grafting materials can be considered a safe alternative, understanding their clinical performance, especially resorption stability, is pivotal. The present case report demonstrates a limited resorption of the allogeneic bone block and further emphasizes the practicability of determining bone resorption by the here introduced method. As our investigation comprises solely one subject, the results should be considered with care and substantiated by further studies., Svrha istraživanja: Svrha ovog prikaza slučaja bila je predstaviti metodu za procjenu volumetrijskih promjena koštanih blokova tijekom cijeljenja i pokazati njezinu izvedivost analizom resorpcije prethodno oblikovanoga alogenoga koštanoga bloka koji se upotrebljava za rekonstrukciju složenoga maksilarnog defekta.Materijal imetoda: CBCT snimke 19-godišnjeg muškarca liječenoga alogenim koštanim blokom učinjene su prije operacije, poslije toga zahvata i šest mjeseci nakon cijeljenja. Skupljanje transplantata procijenjeno je s pomoću dvaju alata za podudaranje slika, odnosno alatima coDiagnostiX ® i Slicer. Biopsijski uzorak uzet je duž kanala implantata tijekom implantacije. Rezultati: Koštani defekt uspješno je rekonstruiran, a nakon ponovnog otvaranja pronađeno je napredno remodeliranje transplantata što je potvrđeno histomorfometrijskom i histološkom analizom. Početni volumeni transplantata određeni alatima coDiagnostiX ® i Slicer bili su 0,373 mL odnosno 0,370 mL, a resorpcija transplantata poslije šest mjeseci cijeljenja iznosila je 0,011 mL (3,00%) i 0,016 ml (4,33%). Zaključci: Izbjegavanje uzimanja kosti i smanjenje invazivnosti važan su problem u dentoalveolarnim rekonstrukcijama. Najoprije nego što se materijali za presađivanje mogu smatrati sigurnom alternativom, ključno je razumjeti njihovu kliničku učinkovitost, posebno stabilnost na resorpciju. Ovaj prikaz slučaja pokazuje ograničenu resorpciju alogenoga koštanoga bloka i dodatno ističe izvedivost određivanja resorpcije kosti ovdje predstavljenom metodom. Kako naše istraživanje obuhvaća samo jedan slučaj, rezultate treba pozorno razmotriti i potkrijepiti daljnjim istraživanjima.

Objective To analyze if general factors such as age, gender, dominant side, fasting blood sugar level, BMI (body mass index), smoking, and drinking play a role in graft resorption after arthroscopic autologous scapular spine bone grafting. Methods From July 2016 to August 2018, patients who were diagnosed with anterior shoulder instability with subcritical bone loss (10%–15%) and underwent arthroscopic autologous scapular spine bone graft transplant were retrospectively reviewed and enrolled in this study. The age, gender, dominant side, fasting blood sugar level, BMI, smoking, and drinking conditions of the enrolled patients were recorded. The graft resorption rate at postoperative 1 year was also measured on three‐dimensional computed tomography (3D‐CT) scans. The Pearson test and the Spearman test were used to identify any significant correlation between the general factors and graft resorption rate. Results A total of 27 patients who underwent arthroscopic autologous scapular spine bone graft for recurrent shoulder instability qualified and were included in this study. There were 20 males and seven females, the mean age was 30.8 ± 9.4 years, the mean follow‐up time was 29.3 months (range, 25–39 months), during which no severe complications such as infection, neurovascular injury, or re‐dislocation were observed. The bone graft healed in all cases, the mean healing time was 2.6 ± 0.5 months (range, 2–3 months). At the last follow‐up, the mean Constant–Murley score was 89.74 ± 3.71, the mean Disabilities of Arm, Shoulder and Hand (DASH) score was 9.77 ± 5.31, and the mean visual analogue score (VAS) was 0.74 ± 0.64. The apprehension test was all negative at final follow‐up. The fasting blood sugar level was 4.78 ± 0.42 mmol/L, BMI was 23.70 ± 4.70. Five patients were “smoking” and 22 “non‐smoking”, four patients were “drinking” and 23 were “non‐drinking.” The graft resorption rate at postoperative 1 year was 19.4% ± 7.5%. The Pearson test and the Spearman test showed no significant correlation between age, gender, dominant side, fasting blood sugar level, BMI, smoking, drinking, and graft resorption rate. Conclusion Age, gender, dominant side, fasting blood sugar level, BMI, smoking, and drinking were not significantly correlated with graft resorption after the arthroscopic autologous scapular spine bone graft for recurrent shoulder instability., We innovatively treat recurrent shoulder instability with arthroscopic autologous scapular spine bone graft and consequently explore the correlation between patient's age, gender, dominant side, fasting blood sugar level, BMI, smoking, drinking, and graft resorption rate.

We describe here a rare case of septic pseudarthrosis due to Erysipelatoclostridium ramosum in a female young patient. The patient, currently in remission from Ewing’s sarcoma treated by a bone resection and allograft combined with chemotherapy, suffered from a chronic femoral pseudarthrosis in a context of bone insufficiency and graft resorption. A broad range 16S PCR followed by sequencing, as well as an enrichment culture of a bone biopsy revealed the presence of E. ramosum, an anaerobic firmicute with a low Gram-positive affinity staining and low GC content, that was further characterized by whole genome sequencing (WGS). Keywords: Clostridium ramosum, Erysipelatoclostridium ramosum, Pseudoarthrosis, Graft resorption, Bone insufficiency, Taxogenomics, Bacterial genomics

BACKGROUND In recent years, there is an increasing tendency to use diced cartilage grafts in rhinoplasty surgery for improving dorsum contour irregularities. This study was designed to compare graft resorption between three techniques of diced cartilage using surgical blade, electrical grinder and grater in rabbit model. METHODS Thirteen New Zealand rabbits were divided into three groups. Three 2×2 cm cartilage specimens were harvested from one of their ears. In group one, the cartilage was diced by use of No:11 surgical blade to o.5 to 1 mm cube pieces. In group two, an electrical grinder was used and in group three, a grater was applied. The grafts were placed in three subcutaneous pockets in the back of rabbits and after 12 weeks, the implants were removed and their weight and volume were recorded and were evaluated by histological techniques. RESULTS There was no difference between the three methods in the 3 groups for graft resorption. There was no change in the volume, but the weight showed a decrease in the control group. CONCLUSIONS As the histological results had no statistically difference between groups, we may recommend use of these two techniques in reconstructive and in aesthetic cases.

Bone morphogenic proteins, BMPs, are a group endogenous proteins that are highly conserved through evolution. The amino acid sequences of about 15 different BMPs are now known and recombinant human BMPs are commercially available. Implantation of an individual BMP protein is sufficient to induce bone formation even at a subcutaneous site. Our initial studies discovered inhibition of bone formation by BMP-2 implanted in a titanium chamber model in rabbit tibia. This paradoxical effect was previously unknown, and lead to studies trying to elucidate the required conditions for BMPs to induce bone formation. Inhibition of bone formation was still found, despite testing different doses of BMP-2, another BMP (OP-1), a different carrier, and altered microenvironment. Stimulation of bone formation by BMP-2 was finally shown in a similar titanium chamber model by adding micromotion. The used titanium model induces minimal fracture surfaces when implanting the BMP and thus a minimal trauma unless micromotion was added. Therefore, we conclude that a certain amount of trauma probably is a prerequisite for BMP induction of bone formation. Impaction of morselized allografts in rat titanium chamber models slowed down new bone ingrowth. This delay was overcome by adding OP-1 to the impacted graft. A marrow-like cavity forms by resorption behind the bone ingrowth frontier in impacted bone allografts. In situations where the graft must resist deformation during remodeling, this resorption might compromise the final result. Bisphosphonates bind to the mineral phase of bone and induce cell death to osteoclasts resorbing the bone. By treating impacted allografts in rats with a bisphosphonate we increased the bone density (both new bone and remaining graft) after 6 weeks. When treating allograft with both a bishosphonate and a BMP (OP-1) the previous increase in new bone ingrowth by OP-1 was lost, suggesting that, at least in some grafting situations, resorption may be a prerequisite for stimulation of bone ingrowth by a BMP. I ben finns tre olika sorters celler, osteoblaster, osteocyter och osteoklaster. Osteoblaster och osteocyter härstammar från stamceller som kallas stödjevävnadens stamceller och svarar för uppbyggnad och upprätthållande av benvävnaden medan osteoklasterna härstammar från de blodbildande stamcellerna och står för nedbrytning av ben. Ben är den enda vävnaden i kroppen som har förmågan att läka helt utan mikroskopiskt synliga ärr, men frakturläkning är en långsam process som leder till långa immobiliseringstider med obehag för patienten och sjukskrivning. Benläkningsprocessen styrs och regleras via ett förutbestämt schema som utlöses i frakturögonblicket. Detta är delvis känt och innefattar bla frisättning av s.k. benmorfogena proteiner. BMP, TGF-ß och biphosphonater 1965 visade Urist att ben, där mineralen tagits bort (demineraliserat benmatrix, DBM), bildade ben när det inopererades i muskel på kanin och råtta. Detta ledde till jakten på ämnet som skulle frälsa världen från ortopediska problemsituationer såsom utebliven frakturläkning, bindvävsläkning istället för benläkning och dålig omvandling av icke kroppseget transplanterat bengraft till kroppseget ben. Ett ton koben gick åt för att fastställa aminosyrasekvensen av dessa första proteiner som döptes till "benmorfogena proteiner", BMP, och sedermera visade sig tillhöra en större grupp proteiner som kallas "transforming growth factor beta", TGF-ß. TGF-ß familjen är en stor grupp proteiner med många olika effekter, bl.a. modulerar de immunsystemet. TGFß-1,2 och 3 har visat sig kunna stimulera benbildning i vissa studier, men hämmar den i andra och det verkar som om effekten beror på vilken experimentmodel som används. Olika BMPs aminosyrasekvens är mycket lika mellan olika djurarter och den största överensstämmelsen med däggdjurens återfinns i bananflugan. Idag har man identifierat ca 15 BMP som visat sig ha många olika effekter. Frånsett benbildning är olika BMP även delaktiga i fosterutveckling vid anläggandet av armar, ben, hjärta, njurar, testiklar, hjärna och tänderna. Bifosfonater är läkemedel som används inom osteoporosbehandlingen. De binder starkt till mineraldelen av ben och inducerar celldöd i de osteoklaster som bryter ner benet. Vid situationer när bengraft inopereras vill man att graftet ska omvandlas till kroppseget levande ben, vilket innebär att både nedbrytningen av graft och uppbyggnaden av nytt ben skall ske parallellt. Ibland är man beroende av graftet för hållfasthetens skull och om då nedbrytningen föregår uppbyggnaden kan den mekaniska hållfastheten riskeras. Det är visat att både stödjevävnadens och de blodbildande stamcellerna kan stimuleras av BMP så att de bildar osteoblaster respektive osteoklaster. Båda är delaktiga i frakturläkningsprocessen och denna avhandling har i huvudsak undersökt två olika BMPs förmåga att påverka benbildningen utifrån olika förutsättningar. Metoder och delarbeten Vi har använt titankammare inopererade i skenbenen på råtta och kanin. Kamrarna har kontakt med de benbildande cellerna i skenbenet och ben växer in i kammaren. Efter en viss tid skördas den inväxta benvävnaden. Man kan därefter histologiskt studera och mäta mängden ben som vuxit in i kammaren. Kaninkammaren växer fast i benet på 6 veckor. Den kan öppnas via en liten hudincision och man kan på så sätt skörda och inplantera, t.ex. proteiner man önskar studera. Det kan göras upprepade gånger. Kaninkammaren finns också som en variant vilken kan ruckas från utsidan och man kan då efterlikna en instabil fraktursituation. Råttkammaren opereras däremot in samtidigt med det material man önskar studera och råttan avlivas när preparaten uttages. Vi har studerat effekten av proteiner (BMP-2, BMP-7, TGFß-1) samt en bifosfonat vad avser beninväxt in i olika material såsom hydroxylapatit, kollagen typ-1 och bengraft. I delarbete I använde vi råttkammaren som fylldes med hydroxylapatit behandlat med antingen TGFß-1 eller BMP-2 i olika doser och fann att TGFß-1 hämmade benbildningen med stigande doser medan BMP-2 ökade benbildningen. I delarbete II lades BMP-2 på en kollagenbit, in i den rigida kaninkammaren varvid vi fann hämning av benbildningen. Delarbete III består av 6 delstudier där vi försökte att klargöra varför den annars förväntade benbildningsstimuleringen av BMP, hämmade benbildningen i den rigida kaninkammaren i delarbete II. Vi konstaterade att hämningen kvarstod trots a) lägre doser, b) utbyte av BMP-2 mot BMP-7 och c) byte av kollagenbäraren mot hydroxylapatitbärare. d) Vi modifierade kammaren för att celler utanför också skulle få tillträde utan att finna stimulering och e)vi lyckades inte identifiera cystbildning. f)BMP-2 på kollagen stimulerade dock beninväxten kraftigt i råttkammaren. I delarbete IV upprepade vi försöket med BMP-2 på kollagen, men denna gång i den ruckbara kaninkammaren, och utsatte kammaren för dagliga vridningar i 3 veckor. Benbildningen stimulerades då ånyo . I delarbete V studerade vi bengraft i kammaren, och fann att hårt packade graft fördröjer ny beninväxt. Vi kunde inte påvisa att det berodde på immunologiskt ofördelaktiga faktorer. Däremot kunde denna fördröjning helt elimineras och faktiskt vändas till stimulering av beninväxtdistansen mha tillsatt BMP-7. I delarbete VI studerade vi bengraft med 2 olika bendensitetsnivåer som behandlats med bifosfonat eller BMP-7 samt kombinationer av de båda. Bendensiteten i graftet vid experimentets slut ökade kraftigt efter behandling med bifosfonat. Kombinationsbehandling med BMP-7 plus bifosfonat åstadkom en hög bendensitet men den positiva effekten på beninväxtdistansen av BMP-7 kvarstod endast om ursprungsgraftet var hårt packat. Sammanfattning Den hämmande effekten av tillsatt BMP i den rigida kaninkammaren är oväntad och därför intressant. Att vi kunnat vända hämningen till stimulering i en instabil kaninkammare, där dagliga vridningar kan likställas med tillfogad skada, antyder att benbildningsförmågan har att göra med traumat eller något som traumat utlöser, ev. en inflammatorisk reaktion. Situationer med stort vävnadstrauma är de vanligaste modelluppställningarna när det gäller att påvisa positiv effekt på benbildningen av BMP i djurmodeller (Tabell 1). Modeller med minimalt vävnadstrauma, som vår rigida kaninkammare, där det enda trauma som tillförs består i att ta ut en benbit och på så sätt åstadkomma en frakturyta på 2x1 mm2 är ovanliga. I situationer med moderat vävnadstrauma har BMP-7 inte överträffat gängse behandling (Jeppsson et al. 1999; Laursen et al. 1999; Friedlaender et al. 2001; Johnsson et al. 2002). Vid stora trauma, har BMP-7 visat lovande resultat enligt preliminära data från en stor multicenterstudie där man behandlar öppna underbensfrakturer med BMP-2 (Govender et al. 2002). Om graden av trauma likställs med den inflammatoriska process som sätts igång, föreligger nu data för att prostaglandin E2 är essentiell för normal rekrytering och utmognad av osteoblaster från bindvävens stamcellspopulation (Zhang et al. 2002) vilket därmed skulle kunna förklara de varierande svaren på tillfört BMP. BMP stimulerar även osteoklaster (Kanatani et al. 1995; Kaneko et al. 2000) och man skulle kunna tänka sig att BMP-effekten på osteoklasterna kvarstår trots utebliven stimuli på osteoblasterna vid minimalt vävnadstrauma. Omvandlandet av icke kroppseget graft till eget ben förlångsammas av att man packar graftet hårt. Vi har inte kunnat visa att det spelar någon roll om graftet är immunokompatibelt eller ej, men vid tillsättande av BMP-7 fann vi att beninväxtdistansen överträffade t.o.m. den som hittas i icke packade graft. Dock fann vi att benkvaliteten bakom beninväxtfronten var märgliknande, med låg bendensitet och det är möjligt att detta även kan bero på BMPs förmåga att stimulera osteoklaster. För att kompensera för BMP-stimuleringen av osteoklaster vid tillfällen då mekanisk integritet är nödvändig under hela remodelleringen provade vi kombinationsbehandling med BMP och bifosfonat på graft med varierande bendensitet. Detta gav mycket hög densitet av benet efter 6 veckor men bifosfonateffekten slår ut positiva effekter av BMP-7 förutom i mycket kraftigt packade graft.