Abstract. Methodology. Prospective single-surgeon case-series evaluating patients undergoing surgery by this technique. 76 cases (mean age of 33.2 years) who had primary ACL reconstruction with BTB or quadriceps tendon with bone block, were divided into 2 matched groups (age, sex and type of graft) of 38 each based on the method of femoral fixation used (interference screw or adjustable cortical suspension). Patients were followed up clinically and using PROMS from NLR with EQ-5D, KOOS, IKDC and Tegner scores. Complications and return to theatre were noted. Paired two-tailed student t-tests and Chi-square tests were employed for statistical analysis. Results. At a mean follow-up of 82 months, peri-operative mean EQ-5D VAS, EQ-5D Index, KOOS, IKDC and Tegner activity scores showed significant improvement (p<0.05), but no significant difference between the two groups (p>0.05). Mean graft length and diameter was 77mm and 9.3 respectively. Mean interval from injury to surgery was 10.5 months. 18(23.7%) patients had associated meniscal tear with 73.3 % undergoing repair. 10 cases (13.2 %) returned to theatre including, MUA for arthrofibrosis (n=2) and intra-substance graft failure (n=2). 3 cases had to be converted to interference screw fixation due to the tightrope cutting through from the femoral bone block as a result of a technical pitfall. Conclusion. Primary ACL reconstruction using adjustable cortical suspension on femoral side for BTB or quadriceps bone-block tendon graft is a safe technique with added advantages of 360 degree bone ingrowth and no screw in the femoral tunnel

Occlusion of the femoral canal is an important step in cemented hip arthroplasty. The goal of occlusion is to allow cement pressurisation and prevent cement egress into the femoral diaphysis. There are numerous designs of cement plugs made out of different materials but there is no consensus or clinical guideline for the choice of cement restrictors. At our centre two types of plugs are used – autologous bone block from femoral canal and the gelatine C-plug (Depuy International). We conducted this study to evaluate the stability of these two plugs and their effect on quality of cementation. The purpose of our study was to assess retrospectively both the length of the “cement tail” i.e. the length of the cement column distal to the stem tip and the cement mantle quality in both groups. A retrospective comparative review was designed after approval from the local R & D department. Power analysis indicated that a minimum of 74 patients per group would be needed. A total of 203 consecutive patients were analysed, 89 received an autologous bone block and 114 had C-plugs. Apart from the plugs both the groups were treated similarly with regards to surgical approach, cementing and operative technique. Surgical technique was to achieve adequate pressurisation and a minimum length of cement tail. Immediate post-operative radiographs were used for analysis. The primary outcome measure was the length of the cement tail, i.e. the length of the cement column from the tip of the stem. The secondary outcome measure was the quality of cementing which was quantified using Barrack's grading. The data was tested for normality using the Shapiro-Wilk test. The means of cement tail lengths in between the two groups were compared using the Wilcoxon ranked sum test. The cementation grades were compared using ANOVA. The correlation between the length of cement tail and the quality of cementation was calculated using ordinal regression. Both the groups were similar in terms of age, sex and primary diagnosis. The mean cement tail length was 6.42 (SE 0.71 mms; range-0–31) in the bone block group and 17.11 (SE-1.34 mms; range 0–65.7 mms) in the C-plug group. This difference was statistically significant (p< 0.0001). The proportion of patients with good quality of cementation (grade A) was significantly higher in the bone block group (80.6%) as compared to the C-plug group (56%) (p < 0.0001). There was a negative correlation between the length of the cement tail and the Barrack grade (rho=0.398), indicating that a short cement tail is associated with better quality cementation. Quality of cementation is of paramount importance in cemented hip arthroplasty. Revision surgery can be more difficult and higher risk in the presence of a long cement tail. We have shown that better quality cementation and shorter cement tails can be achieved with the cheapest of all options for canal occlusion, an autologous bone block and recommend its use

Purpose of the study: Sports activities requiring antepulsion, adduction and medial rotation can favor the development of posterior instability of the shoulder. Conservative treatment is indicated, but many techniques have been proposed in case of failure. All do not allow recovery of the same sports level. We report our experience with six cases of posterior shoulder instability treated with a Gosset posterior bone block. Material and methods: We retrospectively reviewed cases treated between 1974 and 1995. Six athletes, aged 17 to 34 years (mean 25 years) underwent posterior bone block surgery using the Gosset procedure on their dominant shoulder. Three of the patients had experienced involuntary dislocation and three others involuntary and voluntary dislocation. One patient had a multidirectional hyperlaxity. Five patients had participated in rehabilitation programs for at least five months. Two patients had undergone unsuccessful bone block surgery in another unit. Results: Stability and pain relief were achieved in all cases. Three patients recovered complete mobility. In the three others, mean limitation of mobility for the different sectors was 15°. There has been no sign of osteoarthrosis at three years follow-up. All patients have resumed their sports activities, three at the same level. Discussion: In our experience, most surgical techniques proposed for the treatment of posterior shoulder instability are unsuccessful. The Gosset iliac bone block prolongs the articular surface. After consolidation, it allows sports activities requiring shoulder force and provides satisfactory mobility

Purpose of the study: Posterior shoulder instability is a rare condition. Several surgical treatments have been proposed. Material and methods: This was a retrospective series of 21 posterior bone block procedures performed between 1984 and 2001 and analyzed with mean follow-up of six years. Fifteen patients (n=16) had experienced one or more episodes of posterior dislocation. Thirteen patients were athletes and five had traumatic subluxation with chronic posterior instability. Voluntary recurrent dislocations were not observed in these patients. Male gender predominated (n=19 men, 1 woman). Mean age at surgery was 24.8 years (range 17–40). The dominant side was involved in 12 patients (57%). The Constant and Duplay scores were noted as were the pre- and postoperative x-ray findings. There were ten glenoid fractures, two glenoid impactions, ten anterior humeral notches. Mean retroversion, measured on the scans (n=17) was 9.6° (range 0–21°). Results: All patients (n=20) were satisfied or very satisfied. At last follow-up, the mean Constant score was 93.3 (range 80–103) and the mean Duplay score (n=21) 85.6 (40–100); 68.2% of patients (n=15) resumed sports activities at the same level. Failure was noted in three patients, one with recurrent posterior dislocation and two with major apprehension. For two patients, glenohumeral osteoarthritis developed postoperatively. Discussion: Most of the series in the literature have reported results for patients with recurrent posterior subluxations and not for traumatic posterior dislocation, the much more uncommon entity presented here. The rate of bony lesions was high in our series compared with former series in the literature. These results can be explained by two facts. The first that this was a group of recurrent posterior dislocations and second that the analysis of the osteoarticular lesions was made on plain x-rays and/or CT scans. For the two cases of glenohumeral osteoarthritis which developed postoperatively, the position of the bone block does not appear to be involved. Conclusion: The posterior bone block remains the treatment of choice for recurrent posterior dislocation. The risk of developing osteoarthritis appears to be low but a longer follow-up would be necessary for confirmation

Introduction and Objectives: The aim of this paper is to provide a detailed description of our arthroscopic technique performed without a bone block and to report the preliminary results of our experience. This technique offers a valid alternative to meniscal allograft application performed with open techniques and/or bone blocks. Materials and Methods: We retrospectively reviewed 57 patients (59 transplants) (May 01 to December 05), 35 patients (37 transplants) and analyzed the results of the subjective Lysholm test, VAS and IKDC. Results: Mean age was 27.26 years, mean follow-up was 38.62 months. Postoperative results of the Lysholm test, subjective IKDC and VAS scale were 86.62, 78.9 y 22.14 respectively, in comparison with preoperative values of 52.25, 44.87 and 68.71. Analyzing results based on the degree of chondral damage, for grades II–III and III–IV fair and poor results were achieved in 47 % of cases and good and excellent results in 53 %. For grades 0 and I–II fair and poor results were achieved in 5.5% of cases and good and excellent results in 94.44%. Discussion and Conclusions: Arthroscopic meniscal implant without a bone block is a technique that decreases the morbidity associated with other procedures and makes it possible to obtain results similar to those in published series, with 75% of good to excellent results (Lysholm). When managing the different variables the greatest variations were seen when comparing degree of chondral lesion with postoperative results using the different scoring systems, but no significant differences were found due to age, type of activity or transplanted meniscus. As other authors have also concluded, the degree of chondral lesion is the main prognostic factor of the functional result obtained with this technique

Introduction: Management of surgical failures of 1st MTP joint is complex. We present a series of 9 patients treated with bone block arthrodesis of the 1st MTP joint. Materials and Methods: 9 patients who underwent bone block arthrodesis of the hallux MTP joint over a three year period were retrospectively identified. Most of the patients had failed fusions and kellers arthroplasty. All 9 patients had pain and deformity of the hallux, 8 patients had limitation of mobility and 6 patients had gait and shoe wear problems. All patients underwent 1st MTP arthrodesis with interpositional tricortical bone blocks, to restore 1st ray length, with additional cancellous bone graft used in three patients. The construct was held with K-wires which were buried under the skin. 3 patients were put in plaster postoperatively. Results: The average age of the patients was 59 years with average follow up of 15 months. The hallux MTP score postoperatively was 78 out of the possible 90. The 1st MTP joint angle improved from 29.17 to 15.33. All the nine patients were satisfied (four rated it excellent and five rated it good) with their outcome, of which six would readily undergo similar operation and three would undergo the operation if there was no other option. Postoperative complications were mostly metalware related with 8 patients having shoe wear problems for which they underwent K-wire removal (usually under a local anaesthetic in the clinic). 4 patients had minor paraesthesia, 3 patients had superficial infection treated with antibiotics and 1 patient had persistent non-union (but was pain free). Conclusion: The results with bone block arthrodesis are satisfactory and have added advantage of restoring the length of the 1st ray

There are good evidence that the distal canal restrictor improves pressurisation. Bone block and Hardinge restrictors are among the commonly used restrictors in UK. During the introduction of cement, the restrictors tend to migrate. The effect may cause significant change in the size and thickness of the cement mantle. One of the determinants of early dramatic failure is the size of the cement mantle. In our study, we compared the cement mantle thickness and amount of migration with Bone block restrictor and with Hardinge restrictor. The measurements were done in the standard AP x-ray of the hip taken in the post operative period. All cases were operated by one surgeon. The position of the either of the restrictor were maintained in all cases to 1.5 cm below the tip of the stem. Measurements were made for the cement mantle thickness, the distance between the tip of the stem and restrictor and canal diameter. One observer who was not involved in the operative procedure evaluated 69 x-rays. Twenty seven cases of bone block restrictor and 42 cases of Hardinge restrictors were used. At the end of our study, we conclude that both restrictors migrate with pressurisation. The amount of migration with Hardinge restrictor is more than bone block restrictor (21.5mm Vs 14.4mm) which is significant (p-0.007). The amount of migration had not affected the zone-4 cement mantle thickness (p-0.450). With the use of either restrictors, migration was influenced by the canal diameter (p-0.00). Canal diameter did not affect the cement mantle thickness ( p-0.368). We conclude that bone block restrictor is superior in withstanding pressurisation

There are good evidance that the distal canal restrictor improves pressurisation. Bone block and Hardinge restrictors are among the commonly used restrictors in UK. During the introduction of cement, the restrictors tend to migrate. The effect may cause significant chane in the size and thickness of the cement mantle. One of the determinents of early dramatic failure is the size of the cement mantle. In our study, we compared the cement mantle thickness and amount of migration with Bone block restrictor and with Hardinge restrictor. The measurements were done in the standard AP x-ray of the hip taken in the post operative period. All cases were operated by one surgeon. The position of the either of the restrictor were maintained in all cases to 1.5 cm below the tip of the stem. Measurements were made for the cement mantle thickness, the distance between the tip of the stem and restrictor and canal diameter. One observer who was not involved in the operative procedure evaluated 69 x-rays. Twenty seven cases of bone block restrictor and 42 cases of Hardinge restrictors were used. At the end of our study, we conclude that both restrictors migrate with pressurisation. The amount of migration with Hardinge restrictor is more than bone block restrictor (21.5mm Vs 14.4mm) which is significant (p-0.007). The amount of migration had not affected the zone-4 cement mantle thickness (p-0.450). With the use of either restrictors, migration was influenced by the canal diameter (p-0.00). Canal diameter did not affect the cement mantle thickness ( p-0.368). We conclude that bone block restrictor is superior in withstanding pressurisation

Purpose: Between 1979 and 2000, we performed 115 total hip arthroplasties with a bone block, mainly for degenerative hips secondary to congenital dislocation. Up to 1992, we used the classical bone block fixed with a screw and a cemented all-polyethylene Charnley cup inserted in the paleoacetabulum. The drawback of this technique was the two-month delay required for bone healing before weight bearing could be attempted. Since 1992, we have modified this technique, using an embedded bone block impacted into the dihedral angle between the capsule – neoacetabulum and the non-cemented press-fit cup with a screw in the paleoacetabulum. This method allowed immediate postoperative weight bearing, just like after first-intention total hip arthroplasty. Material: Between 1992 and 2002, we operated 56 patients (63 hips) using this technique, 50 (56 hips) were reviewed at a mean five years (range 1 – 9.5). Three patients had died (three hips) and three (four hips) were lost to follow-up. The purpose of this work was to check integration of the bone block and absence of acetabular complications related to early weight bearing. Mean age at surgery was 58.5 years (range 17 – 88). There had been one earlier intervention for 17 hips, two for 13 and three for four. Methods: Physical examination and standard x-rays (AP, lateral, Lequesne oblique views) were available at last follow-up. In addition to the radiographic assessment of the bone block, the Postel Merle d’Aubigné (PMA) objective clinical score and subjective patient satisfaction were recorded. Results: The mean PMA score was 11.7 preoperatively and 17.6 at last follow-up. Ninety-four percent of the patients were very satisfied or satisfied, 6% were dis-satisfied (three postoperative dislocations). Radiographically, we noted block lysis (n=1), non-integrated block (n=8), perfect osteointegration (n=47). The cup showed no radiographic sign of ascension. There were two lucent lines in zone 1 (14.8%) and three in zone 3 (16.8%). There was no relation between bone block integration and presence of acetabular lucent lines. Four complications were recorded: one loosening at eight months, one sudden loosening treated by changing the cup, and three dislocations including one treated four years after implantation by anti-dislocation crescent. There was no relationship between complications and block behaviour. Discussion: The advantage of the embedded block technique with a hybrid prosthesis using a metal-backed polyethylene cup (22.225) is that the postoperative rehabilitation is the same as after a standard prosthesis in good position. Immediate weight bearing on the press-fit cup without cement did not lead to deleterious complications whether clinically or for bone block behaviour. Conclusion: This technique is a reliable method allowing early weight bearing and a shorter recovery time with satisfactory cup stability

Purpose: Unless exposed to stress, bone undergoes lysis. Osteoconduction is not observed in hydroxyapatite in contact with dead bone. We wanted to know whether bone blocks positioned on metal back cups in patients with total hip arthroplasty for acetabular dysplasia are destroyed lysis or “adhere” to the hydroxyapatite. Material and methods: The series included 22 bone blocks in 21 patients with low weight-bearing displacement (n=10), high weight-bearing displacement (n=6), high non-weight-bearing displacement (n=6). Mean follow-up was six years (17 patients > 5 years). Technique: all blocks were fashioned with autologous bone. The size of the cup, and thus the volume of the bone block, was determined by the largest anteroposterior diameter compatible with the desired position. The block was fashioned with a trial cup in place. The definitive cup was inserted separately then lag screwed to the bone block. Implants: twenty-two titanium cups (3 mm) with hydroxyapatite surfacing, bone block width: approximately 28° from the centre of the prosthetic head. Cup position: native acetabulum (n=11), neoacetabulum (n=11). Results: Complications were : sciatic paresia (n=0), displacement (n=0), shift in cup position (n=1 at day 21). Partial lysis of the bone block was observed but there was no case of total lysis. Titanium-hydroxyapatite-block adhesion: no lucent line was visible in 17 cases at more than five years. There were no cases of bony nonunion. Discussion: Are grafts necessary with a metal back cup? The cup is slightly exposed in some primary degenerative hips but all goes well for ten years without a bone block. At what point would cup “exposure” require a bony support? As autograft material is available, it would appear inappropriate to not use it, especially since the lack of lysis suggests grafts are useful. All bony structures behave in an intelligent manner: an oversized bone block undergoes lysis but the part under stress above the cup becomes more dense. Conclusion: Autologous bone blocks placed on metal back cups are not destroyed by lysis. The bone-hydroxyapatite couple adheres normally. Autologous bone blocks above metal back cups behave intelligently, like blocks inserted above cemented polyethylene cups

Introduction: Shoulder relocation is commonly performed for the subluxating or dislocated shoulder secondary to Obstetric Brachial Plexus Palsy (OBPP). We have observed that even when relocation is performed at a young age, remodelling of the immature, dysplastic glenoid is often unreliable, resulting in recurrent incongruity and requiring treatment of the glenoid dysplasia. Methods and results: In a series of 19 patients, we used a posterior bone block to buttress the deficient glenoid at the time of shoulder relocation. At a mean follow up of 28 months (6–73 months), we describe failure in at least 50% with erosion of the bone block, progressive subluxation and resultant pain. A different technique of glenoplasty is now used. An osteotomy of the glenoid is performed postero-inferiorly, elevating the glenoid forward to decrease its volume. Bone graft, often taken from an enlarged and resected coracoid is then packed into the osteotomy and the whole assembly is held with a plate. In a series of 11 patients with a mean age of 6.7 years (1–18 years) we describe good results at short term followup, suggesting that this is a technique warranting further investigation. Conclusion: We believe that where a deficient glenoid is found at surgery for relocation of the shoulder in OBPP, a glenoplasty should be performed at the same time whatever the age of the patient, as glenoid remodelling will not reliably occur. We no longer advocate posterior bone block in these cases as it has a significant failure rate

We evaluated the outcome of hemiarthroplasty with bone block graft and low profile prosthesis (Aequalis. ®. fracture prosthesis) for the comminuted proximal humerus fractures. Sixteen low profile prostheses were used since July 2004, and 11 patients were followed-up for average 19.9 (12–30) months. Their mean age was 67.3 (52–78) years. Cemented stem in all cases. Two bone block graft and cancellous chip bone from resected humeral head. Ten cases for Neer type 4 fracture, one case for type 3 fracture. During 6 weeks, abduction brace with neutral rotation position was maintained. Passive and active range of motion exercise started at 6 weeks. Pain and satisfaction visual analog scale (VAS), range of motion, and modified UCLA score for hemiarthroplasty were evaluated at every visit. Radiography was also checked for stem position, loosening, and tuberosity union. Mean pain VAS was 2.7 (0–5), and mean satisfaction VAS was 8.4 (5–10). Mean active forward flexion was 137o (90–170), external rotation at side was 45.5o (25–70), and internal rotation at back was T10 (T7-L1). Modified UCLA score was 19 (12–30) at final visit. All stems were stable, and there were no loosening at the final follow-up. All tuberosities were united except two tuberosity absorptions. One complication case was infection. The outcome of hemiarthroplasty with bone block graft and low profile prosthesis was comparable to other implants for comminuted proximal humerus fractures. This system had unique advantages for tuberosity union. Further study with more patients and longer follow-up period are necessary to clarify the effectiveness of this prosthesis

Purpose: Posterior instability of the shoulder requires surgical treatment in involuntary forms and after failure of functional treatment. As for anterior instability, a bone block can be fashioned from an iliac graft or a pediculated graft harvested from the acromion. This retrospective analysis concerned the results obtained in eighteen consecutive cases. Material and methods: This series included ten men and eight women, mean age 26 years (15–42) at time of surgery. Fourteen (77%) practised sports activities including four at competition level. Symptoms had persisted for four years on the average. For three patients (16%) posterior instability was expressed by recurrent luxation subluxation. For nine patients (50%) posterior subluxation was a common involuntary event. Six patients suffered from painful shoulders due to an unrecognised posterior instability accident. Diagnosis of posterior instability was establised by arthroscopy in seven patients (39%). For nine shoulders the intervention consisted in a screwed posterior iliac block associated with a tension procedure on the capsule (group 1). For the other nine shoulders the block was harvested from the acromion and pediculated on the deltoid (group 2). Results: Mean follow-up for all patients was eight years. The Duplay score was 75 points at last follow-up. Twelve patients (85% of the athletes) were able to resume their sports activities, half at the same level. Nine patients were pain free. Six patients (33%) had persistent apprehension but did not present true recurrence at physical examination. The Duplay score was 69.4 points in group 1 (follow-up 12 years) and 82.2 points in group 2 (follow-up three years). Thirteen patients (77%) did not have any sign of joint degeneration at last follow-up. One patient had advanced stage IV degeneration related to an intra-articular screw. All patients felt their shoulder had been improved by surgery and one third were disappointed with the results. Discussion: Use of a posterior block is an effective treatent for posterior instability giving results comparable with those obtained with anterior blocks in terms of shoulder stability, pain, recovery of motion, and subjective outcome. This procedure favours joint degeneration less than anterior stabilisation. Results obtained with pediculated acromial blocks are encouraging

Bone defects are frequently observed in anterior shoulder instability. Over the last decade, knowledge of the association of bone loss with increased failure rates of soft-tissue repair has shifted the surgical management of chronic shoulder instability. On the glenoid side, there is no controversy about the critical glenoid bone loss being 20%. However, poor outcomes have been described even with a subcritical glenoid bone defect as low as 13.5%. On the humeral side, the Hill-Sachs lesion should be evaluated concomitantly with the glenoid defect as the two sides of the same bipolar lesion which interact in the instability process, as described by the glenoid track concept. We advocate adding remplissage to every Bankart repair in patients with a Hill-Sachs lesion, regardless of the glenoid bone loss. When critical or subcritical glenoid bone loss occurs in active patients (> 15%) or bipolar off-track lesions, we should consider anterior glenoid bone reconstructions. The techniques have evolved significantly over the last two decades, moving from open procedures to arthroscopic, and from screw fixation to metal-free fixation. The new arthroscopic techniques of glenoid bone reconstruction procedures allow precise positioning of the graft, identification, and treatment of concomitant injuries with low morbidity and faster recovery. Given the problems associated with bone resorption and metal hardware protrusion, the new metal-free techniques for Latarjet or free bone block procedures seem a good solution to avoid these complications, although no long-term data are yet available. Cite this article: Bone Joint J 2024;106-B(10):1100–1110

BACKGROUND. There is no report of additional type of bulk bone grafting (Ad-BG) method with impaction morselized bone graft for reconstruction of shallow dysplastic hip in total hip arthroplasty. The purpose of this study was to define the shallow acetabulum and to evaluate the clinical and radiographic results of primary total hip arthroplasty (THA) with Ad-BG method. MATERIALS and METHODS. With modification of Crowe's classification, shallow dysplasia was defined and classified (Fig. 1). Between October 1999 and August 2008, 120 hips of 302 THAs for dysplastic hip were defined as shallow and Ad-BG was done in 96 hips (80% of shallow hips). For 24 hips with shallow dysplasia, THA were performed by using conventional type of interpositional bulk bone graft (Ip-BG) (8 hips) or without bone graft by using rigid lateral osteophyte. All patients were followed clinically using the Japanese Orthopaedic Association (JOA) score and also Merle d'Aubigne and Postel (M&P) scores in a prospective fashion, and radiographs were analyzed retrospectively. The criteria used for determining loosening were migration or total radiolucent zone between the prosthesis (or bone cement) and host bone. The mean follow-up periods were 8.0 ± 2.3 (5.0–13.5) years. Operative technique. Resected femoral head was sliced with thickness of 1–2 cm, and then a suitable size of the bulk bone block was placed on the lateral cortex of the ilium and fixed by polylactate absorbable screws. Autogenous impaction morselized bone grafting with or without hydroxyapatite granules was performed in conjunction with a cemented socket (Fig. 2). The same surgeon assisted by his colleagues operated all of the cases. RESULTS. No acetabular components were revised except for a case with shallow and Crowe type IV acetabulum. The mean JOA and M&P score for the hips improved from preoperative 39 and 6 points to postoperative 93 and 17 points respectively. Radiographically, the Ad-BGs in most of the cases were remodeled and recognized reorientation within 2 years postoperatively. CONCLUSIONS. The authors report good results of acetabular reconstruction with the use of Ad-BG technique in conjunction with impaction morselized bone graft for shallow dysplastic hip in primary THA. Osteointegration and good clinical outcome were achieved in most of cases. However longer term outcome should be the subject of further investigation

Introduction: In situ subtalar arthrodesis cannot restore anatomical shape of the hindfoot in severe flat foot deformities. Purpose of this paper is to evaluate the result of 250 feet consecutively operated by subtalar arthrodesis with distraction and insertion of a mini structural bone block (SAMBB). Material and Methods: 178 patients (250 feet), mean age 55+/−11 years affected by acquired adult flat foot with subtalar arthritis were evaluated clinically and radiographically and selected to receive SAMBB. Arthrodesis was performed through a 2.5 cm incision, with partial cartilage removal and insertion of a structural corticocancellous block (2 × 1cm), harvested from the proximal ipsilateral tibia, vertically positioned into the sinus tarsi. Associate procedures were Achilles tendon lengthening (124), SERI procedure (61), hind-foot deformity correction (32). Postoperatively plaster-cast without weight-bearing for 4 weeks followed by walking boot was advised. All patients were reviewed at a minimum follow-up of 5 years. Results: Before surgery the mean AOFAS score was 42+/−15, while it was 90+/−8 at follow-up (p< 0.005). Mean heel valgus deviation at rest was 15°+/−8° preoperatively and 6°+/−5° at follow-up (p< 0.005). Mean angulation of Meary’s line at talonavicular joint level was 160°+/−11° preoperatively and 174°+/−8 at follow-up. No complications were found. No or minimal arthritis progression was observed in the ipsilateral foot joints at follow up. Conclusions: SAMBB resulted in an adequate correction of the deformity, with restoration of the anatomical shape of the hind foot and correction of the relationship with the midtarsal joint with no need of hardware. Consequent reduced arthritis progression and excellent clinical result were obtained

To ensure clinical relevance, the in vitro engineering of tissues for implantation requires artificial replacements to possess properties similar to native anatomy. Our overarching study is focussed on developing a bespoke bone-tendon in vitro model replicating the anatomy at the flexor digitorum profundus (FDP) tendon insertion site at the distal phalanx. Anatomical morphometric analysis has guided FDP tendon model design consisting of hard and soft tissue types. Here, we investigate potential materials for creation of the model's bone portion by comparison of two bone cements; brushite and genex (Biocomposites Ltd). 3D printed molds were prepared based on anatomical morphometric analysis of the FDP tendon insertion site and used to cast identical bone blocks from brushite and genex cements. Studies assessing the suitability of each cement type were conducted e.g. setting times, pH on submersion in culture medium and interaction with fibrin gels. Data was collected using qualitative imaging and qualitative measurements (N=3,n=6) for experimental conditions. Both brushite (BC) and genex (GC) cements could be cast into bespoke molds, producing individual blocks and were mixed/handled with appropriate setting times. On initial submersion in culture medium, BC caused a reduction in pH values (7.49 [control]) to 6.85) while GC remained stable (7.59). Reduction in pH value also affected fibrin gel interaction where gel was seen to be detaching/not forming around BC and medium discolouration was noted. This was not observed in GC. While GC outperformed BC in initial tests, repeated washing of BC led to pH stabilisation (7.5,3xwashes), consistent with their further use in this model. This study has compared BC and GC as materials for bone block production. Both materials show promise, and current work assessing material properties and cell proliferation are needed to inform our choice for use in our FDP-tendon-bone interface model. This research was supported by an ORUK Studentship award (ref:533). Genex was kindly provided by Biocomposites, Ltd

The function of the upper extremity is highly dependent on correlated motion of the shoulder. The shoulder can be affected by several diseases. The most common are: rotator cuff tear (RCT), shoulder instability, shoulder osteoarthritis and fractures. Rotator cuff disease is a common disorder. It has a high prevalence rate, causing high direct and indirect costs. The appropriate treatment for RCT is debated. The American Academy Orthopaedic Surgeons guidelines state that surgical repair is an option for patients with chronic, symptomatic full-thickness RCT, but the quality of evidence is unconvincing. Thus, the AAOS recommendations are inconclusive. We are performing a randomized controlled trial to compare surgical and conservative treatment of RCT, in term of functional outcomes, rotator cuff integrity, muscle atrophy and fatty degeneration. Shoulder instability occurs when the head of the upper arm bone is forced out of the shoulder socket. Shoulder instabilities have been classified according to the etiology, the direction of instability, or on combinations thereof. The Thomas and Matsen classification, which is currently the most commonly utilized classification, divides shoulder instability events into the traumatic, unidirectional, Bankart lesion, and surgery (TUBS) and the atraumatic, multidirectional, bilateral, rehabilitation, and capsular shift (AMBRI) categories. The acquired instability overstress surgery (AIOS) category was then added. Surgical procedures for shoulder instability includes arthroscopic capsuloplasty, remplissage, bone block procedure or Latarjet procedure. Reverse total shoulder arthroplasty (RTSA) represents a good solution for the management of patients with osteoarthritis or fracture of the proximal humerus, with associated severe osteoporosis and RC dysfunction

Aims. To draw a comparison of the pullout strengths of buttress thread, barb thread, and reverse buttress thread bone screws. Methods. Buttress thread, barb thread, and reverse buttress thread bone screws were inserted into synthetic cancellous bone blocks. Five screw-block constructs per group were tested to failure in an axial pullout test. The pullout strengths were calculated and compared. A finite element analysis (FEA) was performed to explore the underlying failure mechanisms. FEA models of the three different screw-bone constructs were developed. A pullout force of 250 N was applied to the screw head with a fixed bone model. The compressive and tensile strain contours of the midsagittal plane of the three bone models were plotted and compared. Results. The barb thread demonstrated the lowest pullout strength (mean 176.16 N (SD 3.10)) among the three thread types. It formed a considerably larger region with high tensile strains and a slightly smaller region with high compressive strains within the surrounding bone structure. The reverse buttress thread demonstrated the highest pullout strength (mean 254.69 N (SD 4.15)) among the three types of thread. It formed a considerably larger region with high compressive strains and a slightly smaller region with high tensile strains within the surrounding bone structure. Conclusion. Bone screws with a reverse buttress thread design will significantly increase the pullout strength. Cite this article: Bone Joint Res 2021;10(2):105–112

Introduction. Inadequate stability of the baseplate is a leading cause of revision within reverse total shoulder arthroplasty (rTSA). Micromotion between baseplate and bone is commonly used as a pre-clinical indicator for clinical stability (ASTM F2028-14). Finite element analysis (FEA) has been shown to accurately predict baseplate-bone micromotion, but results may be critically dependent on several modeling assumptions. Here, FEA was used to assess the impact of key modeling assumptions related to screw-bone interactions on various rTSA configurations. Methods. FEA with Ansys ver. 16 was used to simulate a fixation experiment. Baseplates of two different sizes (25mm and 28mm diameter), each with a central screw and four peripheral screws, were virtually implanted in a synthetic bone block. Each baseplate was analyzed using 1.5mm and 3.5mm superior-inferior (SI) offsets of the glenosphere center, as well as using four (‘4S’) and two (‘2S’) peripheral screws. A clinically relevant loading of 756N was applied in compression as well as in inferior-to-superior shear direction through the glenosphere (Figure 1A, 1B). Screw-bone block interactions were modeled in three different ways: (1) Threads were defeatured from the peripheral screws, which were bonded to the bone block (b-nt); (2) Threads were modeled, while still assuming bonded contact (b-t); (3) Threads were modeled, with frictional contact between threads-bone block (f-t). Micromotion results (Figure 1C) from all 24 simulations (3 screw-bone interactions × 2 baseplate diameters × 2 SI offsets × 2 screw configurations) were compared. Results. Across all 24 configurations, the f-t screw-bone interaction resulted in increased micromotion relative to the corresponding bonded simulations. Differences between the two bonded simulations varied among configurations (Figure 2). Screw configuration: For all baseplate diameters, SI offsets, and screw-bone interactions, the 4S configuration had less micromotion (7–20%) than the corresponding 2S configuration (Figure 2). SI Offset: For all baseplate diameters, screw configurations, and screw-bone interactions, the 1.5mm SI offset configuration predicted higher micromotion than the corresponding 3.5mm SI offset configuration (increase of 5–18%), except for the 25mm baseplate in b-nt condition (12–19% decrease) (Figure 3A). Baseplate diameter: For all screw configurations and SI offsets, the f-t modeling assumption resulted in decreased micromotion (5–12%) for the 28mm baseplate as compared to the 25mm baseplate. This trend was reversed for select screw configurations and SI offsets for the other two (b-nt, b-t) modeling assumptions (Figure 3B). Discussion. This study highlights the importance of FEA model fidelity (the level of rigor with which the screw-bone interface is modeled) on evaluating differential performance between rTSA baseplate configurations within a single design family. Three different levels of rigor were considered, based on whether or not the screw threads were explicitly modeled, and on the level of friction allowed between the screw and the bone block. Results highlight that answers to basic questions on relative baseplate performance (e.g. is a 25mm or 28mm baseplate more stable?) are sensitive to these assumptions, and require adequate model validation. Increased care should be taken when conducting evaluations across multiple device families, when additional variables (e.g. screw pitch/torque) are present that could confound analyses