Introduction. Dislocation after primary total hip arthroplasty (THA) is a devastating and frequent postoperative complication. Many risk factors for dislocation have been identified, however, thus far there has been no consensus whether inflammatory arthritis is a risk factor for dislocation or not. We carried out a prospective study assessing the prevalence of dislocation within 2 years after primary total hip arthroplasty for osteoarthrosis and inflammatory arthritis. Patients and Methods. Between 1996 and 1999 312 patients (342 hips) with either a primary or a posttraumatic osteoarthrosis (OA group) and 59 patients (69 hips) with rheumatoid arthritis or other forms of inflammatory arthritis (IA group) were operated. One single type of prosthesis was implanted (EPF-PLUS. ®. cup and SL-PLUS. ®. stem) using an anterior approach. All dislocations in the two years following surgery were recorded. Both diagnostic groups were compared for known risk factors such as old age, female gender, prior hip surgery, and experience of the surgeon. Radiographs were examined for avulsion fractures of the tip of the trochanter and signs of loosening. The abduction and anteversion angles of the acetabular component were measured. Statistical analysis was performed with the Chi-square test and Student’s t-test. Results. The dislocation rate for inflammatory arthritis patients was significantly greater than that in patients with osteoarthrosis: 10. 1% (7 hips) in the IA group, 2. 9% (10 hips) in the OA group (p = 0. 006). There were no other differences in risk factors favouring dislocation in the IA group, such as old age, female gender, prior hip surgery, experience of the surgeon, trochanteric fractures or malposition of the prosthetic components. All dislocations in the IA group were posterior and occurred without any kind of trauma. In contrast, nearly half of the dislocations in the OA group were anterior and two were of traumatic origin. Discussion. Taking into account the fact that there are no differences in known risk factors for dislocation between our two groups and no differences in complication rate, except for dislocation, we can say that inflammatory arthritis has to be considered an independent risk-factor for dislocation after primary total hip arthroplasty. It may be that inferior quality of the (pseudo) capsule and the muscles stabilising the hip joint due to inflammatory arthritis leads to inadequate soft tissue tension. Another factor can be the concomitant impairments in rheumatoid patients, such as impairments of the upper extremity, ipsilateral knee or contralateral hip, leading to hyperflexion in the operated hip causing a posterior dislocation without trauma

Introduction. Multiple factors contributing to an elevated risk for dislocation after total hip arthroplasty (THA) have been identified. Patient-related risk factors that have been identified are prior hip surgery, old age and female gender. However, there have been no prospective reports whether inflammatory arthritis (IA) is an independent risk factor. Material and methods. From January 1996 to December 1999 427 primary total hip arthroplasties were carried out using one type of uncemented prosthesis: a hydroxyapatite coated EPF-PLUS. ®. cup and a SL-PLUS. ®. stem (PLUS Endoprothetik AG, Rotkreuz-CH). A 28 mm. ball head was used in every hip. To evaluate whether IA is a risk factor for dislocation the incidence and cause of early (< 2 year post-surgery) dislocation in IA hips was compared with those carried out for osteoarthrosis (OA). There were 341 THAs in 311 patients with OA and 69 THAs in 59 patients with IA (mainly rheumatoid arthritis) included in this study. The remaining 17 THAs were for various other reasons and excluded from this study. Statistical analysis of the dichotomous variables was carried out by the chi-square test and the Fisher’s exact test, Student’s t-test was used for the analysis of continuous variables. Results and discussion. Both groups were comparable with respect to the following risk factors: gender, approach (either straight-lateral or anterolateral), position of the acetabular component and experience of the surgeon. Mean age was lower in the IA group than in the OA group: 61. 0 vs 68. 1 years. Furthermore, the incidence of prior hip surgery was higher in the OA group. The incidence of dislocation was 7 out of 69 (10. 1%) in IA hips and 10 out of 341 (2. 9%) in OA hips (p=0. 006). All dislocations in IA where posterior, in OA 5 were posterior and 4 were anterior (1 unknown). No other mechanical factors leading to an increased instability of the hip in IA, such as trochanteric fractures, could be identified. Due to the relatively small numbers a statistical difference in the direction of dislocation could be identified (p= 0. 088). So, IA has to be considered as an independent risk factor for dislocation after THA. Both the polyarticular impairments and the lower quality of the soft tissues in IA could explain this elevated risk. To reduce the incidence of dislocation in IA it therefore seems advisable to pay detailed attention the soft tissues and the position of the prosthetic components in IA at the time of surgery. Also, consideration should be given to the use of an acetabular component with an elevated rim

Dislocation is a serious complication to be avoided in total hip arthroplasty (THA) and its incidence risk increases in revision surgery. Combined anteversion (CA) of the cup and stem is a concept for appropriate implant positioning; however, the effect of functional changes in femoral rotation has not been well investigated. The aim of this study was to investigate whether functional CA, considering femoral rotation, is associated with dislocation in patients undergoing revision THA. Seventy-three patients who underwent revision THA and had at least one year of follow-up with pre- and postoperative supine CT imaging were included. Cup and stem were placed with a target combined angle of 37.3° using Widmer's formula. Anatomical and functional CA was calculated postoperatively using the following formula: Anatomical CA: cup anteversion + 0.7 × anatomical stem anteversion; Functional CA: cup anteversion + 0.7 × (anatomical stem anteversion + femoral rotation). Patient demographics, cup and stem angles, CA and their relationship to dislocation were statistically evaluated. Dislocation was observed in 12 patients. In these dislocated cases, there were no significant differences in cup angle, stem angle and anatomical CA compared to non-dislocated cases. However, dislocated cases showed significantly higher values of functional CA [52.7 ± 17.5° (range, 5.9–69.3) vs. 36.0 ± 12.5° (range, 8.6–68.8), p=0.009] and significant deviation from identical CA [17.3 ± 9.6° (range, 2.8–32) vs. 7.5 ± 7.1° (range, 0.1–28.7), p=0.010]. Functional CA considering femoral rotation was associated with dislocation in revision THA patients. This finding suggests that consideration of femoral rotation may be necessary for implant positioning in revision THA

Introduction. We aim to assess whether radiographic characteristics of the greater tuberosity fragment can predict rotator cuff tears inpatients with anterior shoulder dislocations combined with an isolated fracture of the greater tuberosity. Methods. A retrospective single-centre case series of 61 consecutive patients that presented with anterior shoulder dislocations combined with an isolated fracture of the greater tuberosity between January 2018 and July 2022. Inclusion criteria: patients with atraumatic anterior shoulder dislocation associated with an isolated fracture of the greater tuberosity with a minimum follow-up of 3-months. Exclusion criteria: patients with other fractures of the proximal humerus or glenoid. Rotator cuff tears were diagnosed using magnetic resonance or ultrasound imaging. Greater tuberosity fragment size and displacement was calculated on plain radiographs using validated methods. Results. The case series was composed of 22 men and 39 women with a mean age of 65 years (29 - 91 years). The mean follow-up was 15months and median follow up 8.5 months (3 – 60 months). A rotator cuff tear was diagnosed in 14 patients (16%) and involved the supraspinatus (13), infraspinatus (4) and subscapularis (2). Full-thickness tears occurred in 6 patients and partial-thickness tears in 8patients. The mean time from initial injury to rotator cuff tear diagnosis was 5 months (2 – 22 months). The mean greater tuberosity fragment length was 23.4 mm in rotator cuff tear patients versus 32.6 mm in those without a tear (p = 0.006, CI: -15 - -2). The mean greater tuberosity. fragment width was 11.1 mm in rotator cuff tear patients versus 17.8 mm in those without a tear (p = 0.0004, CI: -10 - -2). There was no significant difference in the super inferior and anteroposterior fragment displacement between the two groups. Conclusion. In patients with shoulder dislocations combined with an isolated fracture of the greater tuberosity, rotator cuff tears are associated with a smaller sized greater tuberosity fragment

THA in patients with acetabular bone defects is associated with a high risk of dislocation. Dual mobility (DM) cups are known to prevent and treat chronic instability. The aim of this study was to evaluate the dislocation rate and survival of jumbo DM cups. This was a retrospective, continuous, multicenter study of all the cases of jumbo DM cup implantation between 2010 and 2017 in patients with acetabular bone loss (Paprosky 2A: 46%, 2B: 32%, 2C: 15% and 3A: 6%). The indications for implantation were revisions for aseptic loosening of the cup (n=45), aseptic loosening of the femoral stem (n=3), bipolar loosening (n=11), septic loosening (n=10), periprosthetic fracture (n=5), chronic dislocation (n=4), intraprosthetic dislocation (n=2), cup impingement (n=1), primary posttraumatic arthroplasty (n=8), and acetabular dysplasia (n=4). The jumbo cups used were COPTOS TH (SERF), which combines press-fit fixation with supplemental fixation (acetabular hook, two superior flanges with one to four screws, two acetabular pegs). A bone graft was added in 74 cases (80%). The clinical assessment consisted of the Harris hip score. The primary endpoint was surgical revision for aseptic acetabular loosening or the occurrence of a dislocation episode. In all, 93 patients were reviewed at a mean follow-up of 5.3 ± 2.3 years [0, 10]. As of the last follow-up, the acetabular cup had been changed in five cases: three due to aseptic loosening (3.2%) and two due to infection (2.1%). The survivorship free of aseptic loosening was 96.8%. Three patients (3%) suffered a dislocation. At the last follow-up visit, the mean HSS scores were 72.15, (p < 0.05). Use of a jumbo DM cup in cases of acetabular bone defects leads to satisfactory medium-term results with low dislocation and loosening rates

Dual-mobility (DM) bearings are effective to mitigate dislocation in revision total hip arthroplasty (THA). However, data on its use for treating dislocation is scarce. Aim of this study was to compare DM bearings, standard bearings and constrained liner (CL) in revision THA for recurrent dislocation and to identify risk factors for re-dislocation. We reviewed 100 consecutive revision THAs performed for dislocation from 2012 and 2019. 45 hips (45%) received a DM construct, while 44 hips (44%) and 11 hips (11%) had a standard bearing and CL, respectively. Rates of re-dislocation, re-revision for dislocation and overall re-revision were compared. Radiographs were assessed for cup positioning, restoration of centre of rotation, leg length and offset. Risk factors for re-dislocation were determined by cox regression analysis. Modified Harris hip scores (mHHS) were calculated. Mean follow-up was 53 months (1 to 103). DM constructs were used more frequently in elderly patients (p=0.011) and hips with abductor deficiency (p< 0.001). The re-dislocation rate was 11.1% for DM bearings compared with 15.9% for standard bearings and 18.2% for CL (p=0.732). Revision-free survival for DM constructs was 83% (95% CI 0.77 – 0.90) compared to 75% (95% CI 0.68 – 0.82) for standard articulations and 71% (95% CI 0.56 – 0.85) for CL (p=0.455). Younger age (HR 0.91; p=0.020), lower comorbidity (HR 0.42; p=0.031), smaller heads (HR 0.80; p=0.041) and cup retention (HR 8.23; p=0.022) were associated with re-dislocation. Radiological analysis did not reveal a relationship between restoration of hip geometry and re-dislocation. mHHS significantly improved from 43.8 points to 65.7 points (p<0.001) with no differences among bearing types. Our findings suggest that DM bearings do not sufficiently prevent dislocation in revision THA for recurrent dislocation. Reconstruction of the abductor complex may play a key role to reduce the burden in these high-risk patients

A fracture of the tuberosity is associated with 16% of anterior glenohumeral dislocations. Manipulation of these injuries in the emergency department is safe with less than 1% risk of fracture propagation. However, there is a risk of associated neurological injury, recurrent instability and displacement of the greater tuberosity fragment. The risks and outcomes of these complications have not previously been reported. The purpose of this study was to establish the incidence and outcome of complications associated with this pattern of injury. We reviewed 339 consecutive glenohumeral dislocations with associated greater tuberosity fractures from a prospective trauma database. Documentation and radiographs were studied and the incidence of neurovascular compromise, greater tuberosity fragment migration and intervention and recurrent instability recorded. The mean age was 61 years (range, 18–96) with a female preponderance (140:199 male:female). At presentation 24% (n=78) patients had a nerve injury, with axillary nerve being most common (n=43, 55%). Of those patients with nerve injuries 15 (19%) did not resolve. Greater tuberosity displacement >5mm was observed in 36% (n=123) of patients with 40 undergoing acute surgery, the remainder did not due to comorbidities or patient choice. Persistent displacement after reduction accounted for 60 cases, later displacement within 6 weeks occurred in 63 patients. Recurrent instability occurred in 4 (1%) patients. Patient reported outcomes were poor with average EQ5D being 0.73, QDASH score of 16 and Oxford Shoulder Score of 41. Anterior glenohumeral dislocation with associated greater tuberosity fracture is common with poor long term patient reported outcomes. Our results demonstrate there is a high rate of neurological deficits at presentation with the majority resolving spontaneously. Recurrent instability is rare. Late tuberosity fragment displacement occurs in 18% of patients and regular follow-up for 6 weeks is recommended to detect this

The primary aim of this study was to determine dislocation and revision total hip replacement (THR) up to ten years following primary THR, as well as rates of polyethylene wear, in patients previously enrolled in a randomised controlled trial (RCT) which compared 28 mm and 36 mm metal on highly cross-linked polyethylene (XLPE) articulations. 328 primary THR patients were enrolled in the RCT in Australia. Dislocation was identified from hip instability and hospital visit questionnaires completed by patients or, if they were unable to do so, by their next of kin or primary carer, or General Practitioner. All reported dislocations were confirmed radiographically. Patients' names were cross-matched with the Australian National Joint Replacement Registry to determine whether the index hip had undergone revision THR. Linear wear was measured on plain radiographs using PolyWare (Rev 5, Draftware Developers, Vevay IN, USA). A separate RCT examined the mean proximal wear rate of 28 and 36 mm articulations using radiostereometric analysis (RSA). At 10 years, 110 patients were deceased and 3 patients were lost to follow-up. Overall, dislocation was identified in 8 of 167 (5%) patients with a 28 mm articulation and 2 of 158 (1%) patients with a 36 mm articulation. Three patients experienced recurrent dislocation; all had a 28 mm articulation. 320 (163 28 mm; 157 36 mm) patients were successfully cross-matched with Registry data to identify revision THR. Three patients, all with a 28 mm articulation, underwent revision because of dislocation. Other reasons for revision were infection (1:2), periprosthetic fracture (0:3), loosening/lysis (1:2) and liner fracture (0:1). Adequate radiographs were available to measure wear in 122 hips (67:55) using PolyWare. Excluding bedding in, the mean annual linear wear rate from 1–10 years was 0.04 mm/yr for both 28 and 36 mm articulations (p=0.48). The more sensitive RSA data indicated that at 7 years following primary THR, the mean annual wear rate did not exceed 0.02 mm/yr with either articulation. Up to 10 years following primary THR, 36 mmm articulations were associated with fewer dislocations and revisions for dislocation and did not increase the mean annual linear wear rate

Dislocation post THA confers a higher risk of re-dislocation (Kotwal et al, 2009). The dual mobility (DM) cup design (1974) was aimed at improving the stability by increasing the femoral head to neck ratio (Cuthbert et al., 2019) combining the ideas of low friction arthroplasty with increased jump distance associated with a big head arthroplasty. Understand the dislocation rates, rates of aseptic loosening, infection rate and revision rates between the 2 types of constructs to provide current and up-to date evidence. Medline, pubmed, embase and Cochrane databases were used based on PRISMA guidelines. RevMan software was used for the meta-analysis. Studies (English literature) which used DM construct with atleast 6 months follow-up used as intervention and non DM construct as control were included. 2 independent reviewers conducted the review with a third reviewer in case of difference in opinion regarding eligibility. Primary outcome was dislocation rate and secondary outcome was rate of revision. 564 articles identified out of which 44 articles were screened for full texts and eventually 4 systematic review articles found eligible for the study. Thus, study became a review of systematic reviews. From the 4 systematic reviews, another 35 studies were identified for data extraction and 13 papers were used for meta-analysis. Systematic reviews evaluated, projected an average follow up of 6-8 years with significantly lower dislocation rates for DM cups. The total number of patients undergoing DM cup primary THA were 30,559 with an average age 71 years while the control group consisted of 218,834 patients with an average age of 69 years. DM group had lower rate of dislocation (p < 0.00001), total lower rate of cup revision (p < 0.00001, higher incidence of fracture (p>0.05). DM THA is a viable alternative for conventional THA. The long-term results of DM cups in primary THA need to be further evaluated using high quality prospective studies and RCTs

Introduction. Orthopaedic rehabilitation of adolescences and young adults with high dislocation of the femur is rather challenging. The role of palliative salvage procedures is controversial enough in the cohort of patients. Materials and Methods. Treatment outcomes of 10 patients with congenital hip dislocation were analyzed. Mean age at intervention was 17,8 years (15–22). The grade of dislocation were assessed according to Eftekhar: type C − 2, type D − 8. The mean baseline shortening was 4.7±0.36 cm. All subjects underwent PSO with the Ilizarov method. Another osteotomy for lengthening and realignment was produced at the boundary of the upper and middle third of the femur. The mean time in the Ilizarov frame was 5.3 months. Results. The mean follow-up was 2.6±.1 years (range, 15 to 32 years). Limb shortening of 1 cm to 1. 1. /. 2. cm was observed in four cases. Functional outcomes according to d'Aubigne-Postel were: Pain 4,4±0,15 points. ROM − 4,1±0,3 points. Walking ability − 4,5±0,2 points. Two cases had good results (15–17 points), and seven patients had fair outcomes (12–14 points). A poor result (7 points) was recorded in one female patient 28 years after PSO followed by THA. Conclusions. Hip reconstruction with the Ilizarov method can be used in specific clinical situations as an alternative salvage procedure to delay THR in young patients with high dislocation of the femur

Background. Postoperative dislocation is one of the main surgical complications and the primary cause for revision surgery after 2-stage implant exchange due to periprosthetic infection of a total hip arthroplasty. Objective. The aims of our study were (1) to determine the incidence of dislocation after two-stage THA reimplantation without spacer placement, (2) to evaluate relevant risk factors for dislocation and (3) to assess the final functional outcome of those patients. Method. We prospectively analyzed 187 patients who underwent a two-stage total hip arthroplasty (THA) revision after being diagnosed with periprosthetic joint infection (PJI) from 2013 to 2019. The mean duration of follow-up was 54.2 ± 24.9 months (>36 months). The incidence of postoperative dislocation and subsequent revision was estimated through Kaplan-Meier curves and potential risk factors were identified using Cox hazard regression. The functional outcome of the patients was assessed using the modified Harris Hip Score (mHHS). Results. The estimated cumulative dislocation-free survival was 87.2% (95% CI: 81.2%-91.3%) with an estimated 10% and 12% risk for dislocation within the first 6 and 12 months, respectively. The use of a dual-mobility construct had no significant impact on the dislocation rate. Increasing body mass index (BMI) (HR=1.11, 95% CI: 1.02-1.19, p=0.011), abductor mechanism impairment (HR=2.85, 95% CI: 1.01-8.01, p=0.047), the extent of elongation of the affected extremity between stages (HR=1.04, 95% CI: 1.01-1.07, p=0.017), the final leg length discrepancy (HR=1.04, 95% CI: 1.01-1.08, p=0.018) and PJI recurrence (HR=2.76, 95% CI: 1.00-7.62, p=0.049) were found to be significant risk factors for dislocation. Overall revision rates were 17% after THA reimplantation. Dislocated hips were 62% more likely to undergo re-revision surgery (p<0.001, Log-rank= 78.05). A significant average increase of 30 points in mHHS scores after second-stage reimplantation (p=0.001, Wilcoxon-rank) was recorded, but no difference was noted in the final HHS measurements between stable and dislocated hips. Conclusion. Dislocation rates after 2-stage THA reimplantation for PJI remain high, especially regarding overweight or re-infected patients. Careful leg length restoration and an intact abductor mechanism seem critical to ensure stability in these complex patients

Abstract. Introduction. Dislocation post THA confers a higher risk of re-dislocation (Kotwal et al, 2009). The dual mobility (DM) cup design (1974) was aimed at improving the stability by increasing the femoral head to neck ratio (Cuthbert et al., 2019) combining the ideas of low friction arthroplasty with increased jump distance associated with a big head arthroplasty. Aims. Understand the dislocation rates, rates of aseptic loosening, infection rate and revision rates between the 2 types of constructs to provide current and up-to date evidence. Methods. Medline, pubmed, embase and Cochrane databases were used based on PRISMA guidelines. RevMan software was used for the meta-analysis. Studies (English literature) which used DM construct with atleast 6 months follow-up used as intervention and non DM construct as control were included. 2 independent reviewers conducted the review with a third reviewer in case of difference in opinion regarding eligibility. Primary outcome was dislocation rate and secondary outcome was rate of revision. Results. 564 articles identified out of which 44 articles were screened for full texts and eventually 4 systematic review articles found eligible for the study. Thus, study became a review of systematic reviews. From the 4 systematic reviews, another 35 studies were identified for data extraction and 13 papers were used for meta-analysis. Systematic reviews evaluated, projected an average follow up of 6–8 years with significantly lower dislocation rates for DM cups. The total number of patients undergoing DM cup primary THA were 30,559 with an average age 71 years while the control group consisted of 218,834 patients with an average age of 69 years. DM group had lower rate of dislocation (p < 0.00001), total lower rate of cup revision (p < 0.00001, higher incidence of fracture (p>0.05). Conclusion. DM THA is a viable alternative for conventional THA. The long-term results of DM cups in primary THA need to be further evaluated using high quality prospective studies and RCTs. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Abstract. Introduction. Traumatic knee dislocations are devastating injuries and there is no single best accepted treatment. This study looked at functional outcome of a single surgeon case series of patients who underwent surgical management of their knee dislocation. Methods. Eighty-seven patients with knee dislocation were treated at a major trauma centre. Acute surgical repair and reconstruction with fracture fixation within 4 weeks was preferred unless the patient was too unstable (Injury severity score>16). The collaterals were repaired and augmented using a variety of autografts, allografts or synthetic grafts. PCL was primarily braced and reconstructed subsequently, if required. Outcome was collected prospectively using IKDC score, KOOS and Tegner score. Results. The mean age of the patients was 33.6yrs (SD 11.9), 66 males and 21 females. According to Schenck classification, 26 were KD-I (30%), 6 KD-II (7%), 13 were KD-III (15%), 7 were KD-IV (8%) and 35 were KD-V (40%). 7 patients had CPN injury (8%), 3 had vascular injury (3.4%), 2 had combined CPN and vascular injury (2.3%). Acute surgical treatment was done in 62 patients while 10 had staged reconstruction. 22 patients had delayed reconstruction. The mean follow-up period was 5.8 years (1- 12 yrs), mean IKDC score was 57.6 (SD 23.6). The mean Tegner activity scale postoperatively was 4.5(SD 2) and the mean KOOS score was 74.9 (SD 19.6). Conclusion. A large proportion of cases were KD-V but still had a good outcome with surgical management. Current classification systems do not cover all dislocation patterns and a modification is proposed

Introduction and Objective. Dislocation of a hip hemiarthroplasty is a significant complication with a high mortality rate in elderly patients. Previous studies have shown a higher risk of dislocation in patients with neuromuscular conditions. In this study, we reviewed our larger cohort of patients to identify if there is a link between neuromuscular disorders and dislocation of hip hemiarthroplasty in patients with neuromuscular conditions. Materials and Methods. We have retrospectively analysed a single-centre data that was collected over 34 years for patients with intracapsular neck of femur fracture who underwent hip hemiarthroplasty. The study population was composed of four groups: patients with no neuromuscular disorders, patients with Parkinson's disease, patients with previous stroke, and patients with mental impairment. Results. A total of 3827 patients were included in the analysis. 3371 patients had no neuromuscular condition (Group I) with a dislocation rate of 1.1%. 219 patients had Parkinsonism (Group II) with a dislocation rate of 3.2%, 104 patients had a previous stroke with weakness on the fracture side with a dislocation rate of 1.0% (Group III), and 984 patients had severe mental impairment with a dislocation rate of 1.8% (Group IV). The increased dislocation rate for those with Parkinson's disease was statistically significant (p=0.02) while none of the other neuromuscular conditions were statistically significant. Conclusions. Our study has shown an increased risk of dislocation of hemiarthroplasty in patients with Parkinson's disease in comparison to other groups. No increase was apparent for patients with mental impairment or weakness from a previous stroke

Abstract. Background. The Oxford Domed Lateral (ODL) Unicompartmental Knee Replacement (UKR) has some advantages over other lateral UKRs, but the mobile bearing dislocation rate is high (1–6%). Medial dislocations, with the bearing lodged on the tibial component wall, are most common. Anterior/posterior dislocations are rare. For a dislocation to occur distraction of the joint is required. We have developed and validated a dislocation analysis tool based on a computer model of the ODL with a robotics path-planning algorithm to determine the Vertical Distraction required for a Dislocation (VDD), which is inversely related to the risk of dislocation. Objectives. To modify the ODL design so the risk of medial dislocation decreases to that of an anterior/posterior dislocation. Methods. The components were modified using Solidworks. For each modification the dislocation analysis tool was used to determine the VDD for medial dislocation (with bearing 0–6mm from the tibial wall). This was compared with the original implant to identify the modifications that were most effective at reducing the dislocation risk. These modifications were combined into a final design, which was assessed. Results. Modifying the tibial component plateau, changing the femoral component width and making the bearing wider medially had little effect on VDD. Shifting the femoral sphere centre medially decreased VDD. Shifting the femoral sphere laterally, increasing tibial wall height and increasing bearing width laterally increased VDD. A modified implant with a femoral sphere centre 3mm lateral, wall 2.8mm higher, and bearing 2mm wider laterally, implanted so the bearing is ≤4mm from the tibial wall with a bearing thickness ≥4mm had a minimum VDD for medial dislocation of 5.75mm, which is larger than the minimum VDD for anterior/posterior dislocation of 5.5mm. Conclusions. A modified ODL design should decrease the dislocation rate to an acceptable level, however, further testing in cadavers is required. Declaration of Interest. (a) fully declare any financial or other potential conflict of interest

Abstract. Background. Dislocation of a hip hemiarthroplasty is a devastating complication with a high mortality rate in elderly patients. Previous studies have suggested a higher dislocation rate in patients with neuromuscular conditions. In this study, we have reviewed our larger cohort of patients to identify whether there is any association between neuromuscular disorders and prosthetic dislocation in patients treated with hip hemiarthroplasty for femoral neck fractures. Patients and Methods. Our study is a retrospective analysis of data collected over 34 years for patients with intracapsular neck of femur fracture who underwent hip hemiarthroplasty. The study population is composed of four groups: patients with no neuromuscular disorders, patients with Parkinson's disease, patients with previous stroke, and patients with dementia. Results. A total of 3827 patients were treated with hip hemiarthroplasty. For the 3371 patients with no neuromuscular condition (Group I) the dislocation rate was 1.1%. 219 patients had Parkinsonism (Group II) with a dislocation rate of 3.2%, 104 patients had a previous stroke with weakness on the fracture side with a dislocation rate of 1.0% (Group III), and 984 patients had severe dementia with a dislocation rate of 1.8% (Group IV). The increased dislocation rate for those with Parkinson's disease was statistically significant (p=0.02) while none of the other neuromuscular conditions were statistically significant. Conclusion. Our study demonstrates an increased risk of dislocation after hemiarthroplasty for patients with Parkinson's disease in comparison to other groups. No increase was apparent for those with dementia or weakness from a previous stroke

Purpose: To report concomitant dorsal dislocation of first metatarsophalangeal joint and divergent Lisfranc dislocation, a uniquely “floating forefoot” and analyse clinical pathodynamics. Methods & Results: We treated concomitant dorsal dislocation of first metatarsophalangeal joint and divergent Lisfranc fracture-dislocation in an intoxicated patient as a heavy weight fell on foot. Closed reduction of first metatarsophalangeal joint was unstable until after open reduction and fixation of first tarsometarsophalangeal joint. First to third tarsometatarsal joints were stabilised with cannulated screws and lateral two rays with Kirschner wires. Prophylactic fasciotomies were performed to preempt potentially high risk of failure of recognition of compartment syndrome in intoxicated patient. Clinical pathodynamic analysis suggests that natural tendency to withdraw the foot contributed to primary medial loading with forced hyperextension of hallux metatarsophalangeal joint and enhanced complementary hyperflexion of midfoot. The former resulted in dorsal dislocation of first metatarsophalangeal joint. Then load shift toward secondary axis of lateral divergent loading became the operative force to produce divergent Lisfranc dislocation, which effectively resulted in a floating forefoot. Conclusions: Floating forefoot is a unique injury after high-energy trauma, although floating metatarsal and association between Jahss Type I complex dislocation of first metatarsophalangeal joint and Lisfranc injury were described. Floating forefoot also represents Grade V in the modified classification of metarsophalangeal injuries (Kodali Siva R K Prasad et al Modification of Clanton’s classification) as progression of injury pattern transcends the local barrier and raises the spectrum of dynamic cascade of multidirectional transmission of the operative forces with the resultant unique injury

Introduction: Preliminary data suggest that immobilization in external rotation may be effective in lowering the incidence of recurrence after first traumatic shoulder dislocation, with a zero reoccurrence rate reported at 15 months follow-up. The purpose of the present study was to ascertain whether this method could lower the incidence of recurrent dislocation in a young, very physically active population. Methods: In an IRB approved prospective study, young males who sustained first traumatic shoulder dislocation were randomized to be treated for four weeks either using a traditional internal rotation brace or a new device which immobilizes the shoulder at 15 to 20 degrees of external rotation. Subjects were then treated according to a standard physical therapy protocol. Follow-up was done at five time points in the first year post dislocation. Subjects with clinically stable shoulders resumed full activity after three months. Differences in outcome were assessed by the chi square test. Results: Thirty nine subjects participated in the study. Thirty of them were soldiers. Twenty four subjects were treated with external rotation braces. At follow-up of between 4 to 28 months, a new dislocation was documented in 8 of the 24 subjects immobilized in external rotation (33%) and in 5 of the 15 subjects immobilized in internal rotation (33 %). No statistical difference (p=1.0) was found between the instability rates of the two treatment groups. Discussion: The present study indicates that even in a short-term follow-up the technique of immobilizing a first dislocation in external rotation was not effective in lowering the incidence of recurrent shoulder dislocations in a young, physically active population

Abstract. Background. Traumatic knee dislocations are devastating injuries and there is no single best accepted treatment. Treatment needs to be customised to the patient taking into consideration injury to the knee; associated neurovascular and systemic injuries. Objective. This study looked at functional outcome of a single surgeon case series of patients who underwent surgical management of their knee dislocation. Methods. Seventy patients with knee dislocation were treated with multi-ligament reconstruction at a major trauma centre. Acute surgical repair and reconstruction with fracture fixation within 3 weeks was preferred unless the patient was too unstable (Injury severity score>16). PCL was primarily braced and reconstructed subsequently, if required. Outcome was collected prospectively using IKDC score, KOOS and Tegner score. Results. The mean age of the patients was 35yrs (17–74), 53 males and 17 females. 5 patients had CPN injury (7%), 3 had vascular injury (4.2%), 2 had combined CPN and vascular injury (2.8%). Acute surgical treatment was done in 48 patients while 10 had staged reconstruction. 22 patients had delayed reconstruction. The mean follow-up period was 4.8 years (1–12 yrs). According to the IKDC score 67% of the patients had near-normal knee function. The mean Tegner activity scale postoperatively was 4.5 (preinjury 6.5) and the mean KOOS score was 75.3. Four patients had stiffness and needed arthroscopic arthrolysis, two patients had a residual foot drop from the original injury and needed tendon transfer. Conclusion. Traumatic knee dislocation is a challenging problem but good outcomes can be achieved by surgical management

Introduction. Dislocated hip hemiarthroplasties (HA) are associated with a 45% revision rate and 40% mortality rate. Implant selection for HA operations vary with no universally accepted implant choice. The WHiTE3 trial suggested older designs such as the Thompson has equitable outcomes to more modern and expensive implants such as the Exeter V40+Unitrax. Our multi-centre consecutive series of NOFs patients treated with HA assesses the impact of surgical and patient factors on dislocation risk. Methods. Medical and radiographic records for patients treated between 1. st. January 2009 and 30. th. September 2017 with a HA at three acute hospitals were reviewed. Implant and dislocation data were recorded. Patient demographics, comorbidities and operation details were extracted from the medical records and NHFD. Patients were excluded if there were no postoperative radiographs or when HA had been performed as a revision procedure. Results. We identified 4305 consecutive patients with 189 excluded. There was no difference in patient characteristics between the hospitals or implant types (p>0.05). Four HA implants were used during the study period; Thompson, Austin-Moore, Furlong and Exeter V40+Unitrax. 63 dislocations were identified (1.5%), median time to dislocation was 24 days. Dislocation rates for Thompson HAs were significantly higher (p=0.004) at 3.7%. No association was demonstrated with cemented versus uncemented, bipolar versus monopolar, fixed versus variable offsets, operating surgeon grade and dislocation rates (p>0.05). Patient factors (preoperative AMTS, postoperative AMTS, preoperative mobility and ASA grade) had no effect on dislocation (p>0.05). Discussion. Our study which is reflective current implant choices, demonstrates that Thompson implants for HA after NOFs have a significantly higher dislocation rates than other common prostheses, and their continued use should be reconsidered. This effect has not been demonstrated in previous studies. Patient, implant construct and surgeon factors had little bearing on the subsequent dislocation rate