Fixation of the glenoid component is critical to the outcome of total shoulder arthroplasty. In an in vitro study, we analysed the effect of surface design and thickness of the cement mantle on the pull-out strength of the polyethylene pegs which are considered essential for fixation of cemented glenoid components. The macrostructure and surface of the pegs and the thickness of the cement mantle were studied in human glenoid bone. The lowest pull-out forces, 20 ± 5 N, were for cylindrical pegs with a smooth surface fixed in the glenoid with a thin cement mantle. The highest values, 425 ± 7 N, were for threaded pegs fixed with a thicker cement mantle. Increasing the diameter of the hole into which the peg is inserted from 5.2 to 6.2 mm thereby increasing the thickness of the cement mantle, improved the mean pull-out force for the pegs tested

Aims. The cemented Oxford unicompartmental knee arthroplasty (OUKA) features two variants: single and twin peg OUKA. The purpose of this study was to assess the stability of both variants in a worst-case scenario of bone defects and suboptimal cementation. Methods. Single and twin pegs were implanted randomly allocated in 12 pairs of human fresh-frozen femora. We generated 5° bone defects at the posterior condyle. Relative movement was simulated using a servohydraulic pulser, and analyzed at 70°/115° knee flexion. Relative movement was surveyed at seven points of measurement on implant and bone, using an optic system. Results. At the main fixation zone, the twin peg shows less relative movement at 70°/115°. At the transition zone, relative movements are smaller for the single peg for both angles. The single peg shows higher compression at 70° flexion, whereas the twin peg design shows higher compression at 115°. X-displacement is significantly higher for the single peg at 115°. Conclusion. Bony defects should be avoided in OUKA. The twin peg shows high resilience against push-out force and should be preferred over the single peg. Cite this article: Bone Joint Res 2022;11(2):82–90

Aims. The aim of this study was to longitudinally compare the clinical and radiological outcomes of anatomical total shoulder arthroplasty (aTSA) up to long-term follow-up, when using cemented keel, cemented peg, and hybrid cage peg glenoid components and the same humeral system. Methods. We retrospectively analyzed a multicentre, international clinical database of a single platform shoulder system to compare the short-, mid-, and long-term clinical outcomes associated with three designs of aTSA glenoid components: 294 cemented keel, 527 cemented peg, and 981 hybrid cage glenoids. Outcomes were evaluated at 4,746 postoperative timepoints for 1,802 primary aTSA, with a mean follow-up of 65 months (24 to 217). Results. Relative to their preoperative condition, each glenoid cohort had significant improvements in clinical outcomes from two years to ten years after surgery. Patients with cage glenoids had significantly better clinical outcomes, with higher patient-reported outcome scores and significantly increased active range of motion, compared with those with keel and peg glenoids. Those with cage glenoids also had significantly fewer complications (keel: 13.3%, peg: 13.1%, cage: 7.4%), revisions (keel: 7.1%, peg 9.7%, cage 3.5%), and aseptic glenoid loosening and failure (keel: 4.7%, peg: 5.8%, cage: 2.5%). Regarding radiological outcomes, 70 patients (11.2%) with cage glenoids had glenoid radiolucent lines (RLLs). The cage glenoid RLL rate was 3.3-times (p < 0.001) less than those with keel glenoids (37.3%) and 4.6-times (p < 0.001) less than those with peg glenoids (51.2%). Conclusion. These findings show that good long-term clinical and radiological outcomes can be achieved with each of the three aTSA designs of glenoid component analyzed in this study. However, there were some differences in clinical and radiological outcomes: generally, cage glenoids performed best, followed by cemented keel glenoids, and finally cemented peg glenoids. Cite this article: Bone Joint J 2023;105-B(6):668–678

Aims. The hypothesis of this study was that bone peg fixation in the treatment of osteochondral lesions of the talus would show satisfactory clinical and radiological results, without complications. Methods. Between September 2014 and July 2017, 25 patients with symptomatic osteochondritis of the talus and an osteochondral fragment, who were treated using bone peg fixation, were analyzed retrospectively. All were available for complete follow-up at a mean 22 of months (12 to 35). There were 15 males and ten females with a mean age of 19.6 years (11 to 34). The clinical results were evaluated using a visual analogue scale (VAS) and the American Orthopaedic Foot and Ankle Society (AOFAS) score preoperatively and at the final follow-up. The radiological results were evaluated using classification described by Hepple et al based on the MRI findings, the location of the lesion, the size of the osteochondral fragment, and the postoperative healing of the lesion. Results. The mean VAS and AOFAS score improved significantly from 6.3 (4 to 8) and 70.6 (44 to 78) preoperatively to 1.6 (0 to 5) and 91.1 (77 to 100) at the final follow-up, respectively (p < 0.001). The classification on MRI was stage 2a in nine patients, stage 3 in 14, and stage 4 in two. The lesion was located on the posteromedial aspect of the dome of the talus in 19 patients, the anterolateral aspect in five, and the centrolateral aspect in one. The mean size of the fragment was 11.2 mm (5 to 20) horizontally, 10.4 mm (7 to 18) vertically, and 5.2 mm (3 to 10) deep, respectively. The postoperative healing state was good in 19 patients and fair in six. Conclusion. Bone peg fixation for osteochondral lesions of the talus showed satisfactory clinical and radiographic results, without complications. This technique could be a good form of treatment for patients with this condition who have an osteochondral fragment. Cite this article: Bone Joint J 2020;102-B(10):1349–1353

Ventral screw osteosynthesis is a common surgical method for treating fractures of the odontoid peg, but there is still no consensus about the number and diameter of the screws to be used. The purpose of this study was to develop a more accurate measurement technique for the morphometry of the odontoid peg (dens axis) and to provide a recommendation for ventral screw osteosynthesis. Images of the cervical spine of 44 Caucasian patients, taken with a 64-line CT scanner, were evaluated using the measuring software MIMICS. All measurements were performed by two independent observers. Intraclass correlation coefficients were used to measure inter-rater variability. The mean length of the odontoid peg was 39.76 mm (. sd. 2.68). The mean screw entry angle α was 59.45° (. sd. 3.45). The mean angle between the screw and the ventral border of C2 was 13.18° (. sd. 2.70), the maximum possible mean converging angle of two screws was 20.35° (. sd. 3.24). The measurements were obtained at the level of 66% of the total odontoid peg length and showed mean values of 8.36 mm (. sd. 0.84) for the inner diameter in the sagittal plane and 7.35 mm (. sd. 0.97) in the coronal plane. The mean outer diameter of the odontoid peg was 12.88 mm (. sd. 0.91) in the sagittal plane and 11.77 mm (. sd. 1.09) in the coronal plane. The results measured at the level of 90% of the total odontoid peg length were a mean of 6.12 mm (. sd. 1.14) for the sagittal inner diameter and 5.50 mm (. sd. 1.05) for the coronal inner diameter. The mean outer diameter of the odontoid peg was 11.10 mm (. sd.  1.0) in the sagittal plane and 10.00 mm (. sd. 1.07) in the coronal plane. In order to calculate the necessary screw length using 3.5 mm cannulated screws, 1.5 mm should be added to the measured odontoid peg length when anatomical reduction seems possible. The cross-section of the odontoid peg is not circular but slightly elliptical, with a 10% greater diameter in the sagittal plane. In the majority of cases (70.5%) the odontoid peg offers enough room for two 3.5 mm cannulated cortical screws. Cite this article: Bone Joint J 2013;95-B:536–42

Fractures of the odontoid peg are common spinal injuries in the elderly. This study compares the survivorship of a cohort of elderly patients with an isolated fracture of the odontoid peg versus that of patients who have sustained a fracture of the hip or wrist. A six-year retrospective analysis was performed on all patients aged > 65 years who were admitted to our spinal unit with an isolated fracture of the odontoid peg. A Kaplan–Meier table was used to analyse survivorship from the date of fracture, which was compared with the survivorship of similar age-matched cohorts of 702 consecutive patients with a fracture of the hip and 221 consecutive patients with a fracture of the wrist. A total of 32 patients with an isolated odontoid fracture were identified. The rate of mortality was 37.5% (n = 12) at one year. The period of greatest mortality was within the first 12 weeks. Time made a lesser contribution from then to one year, and there was no impact of time on the rate of mortality thereafter. The rate of mortality at one year was 41.2% for male patients (7 of 17) compared with 33.3% for females (5 of 15). . The rate of mortality at one year was 32% (225 of 702) for patients with a fracture of the hip and 4% (9 of 221) for those with a fracture of the wrist. There was no statistically significant difference in the rate of mortality following a hip fracture and an odontoid peg fracture (p = 0.95). However, the survivorship of the wrist fracture group was much better than that of the odontoid peg fracture group (p < 0.001). Thus, a fracture of the odontoid peg in the elderly is not a benign injury and is associated with a high rate of mortality, especially in the first three months after the injury. Cite this article: Bone Joint J 2014;96-B:88–93

Background. Glenoid component aseptic loosening is the most common source of total shoulder arthroplasty (TSA) revision. In an attempt to strengthen cemented glenoid component fixation, divergent pegged glenoids were designed. Divergent peg creation was intended to increase cement purchase and provide resistance to component rocking. Methods. Thirty-four patients who underwent divergent peg TSA had data collected prospectively. The data from these patients was retrospectively reviewed, primarily for radiographic evidence of glenoid component loosening. The endpoint was defined as the need for revision secondary to glenoid loosening. Secondary outcome measures such as SPADI (shoulder pain and disability index), active forward elevation, abduction, internal rotation, and external rotation were also collected. Data was obtained preoperatively and at the following postoperative intervals: 3 months, 6 months, and yearly. The last available postoperative radiographs were also reviewed and graded on a modified Franklin glenoid lucency scale described by Lazarus et al. Results. The mean follow-up was 5.6 years ± 2.44 (range, 2–10 years). Of the 34 patients in the study, 20 patients had radiographs available for review. Radiographs showed complete lucency around one or less pegs in 14/20 patients (grade 0–2). Six out of twenty glenoids had complete radiolucency around two or more pegs with gross loosening seen in one shoulder (grade 3–5). No secondary surgery was performed in any patients. Significant improvements were seen in active elevation 30.2 degrees ±44.3 (p=0.043) at the last follow up. Improvement was also seen in internal rotation of 4.3 levels ± 4.9 (p=0.016) at the last follow-up. The mean postoperative SPADI score decreased by 48.1 points (p=0.039). Conclusions. Patients with divergent pegged glenoid TSA showed significant improvement in postoperative shoulder elevation, internal rotation, and SPADI scores at final follow-up. No patients underwent revision. However, there were a significant number of patients with radiolucency seen around 2 or more pegs

Invasive intraneural electrodes implanted in peripheral nerves are neural prosthetic devices that are exploied to control advanced neural-interfaced prostheses in human amputees. One of the main issues to be faced in chronic implants is represented by the gradual loss of functionality of such intraneural interfaces due to an electrical impedance increase caused by the progressive formation of a fibrotic capsule around the electrodes, which is originally due to a nonspecific inflammatory response called foreign body reaction (FBR). In this in vitro work, we tested the biocompatibility and ultra-low fouling features of the synthetic coating - poly(ethylene glycol) (PEG) - compared to the organic polymer - zwitterionic sulfated poly(sulfobetaine methacrylate) (SBMA) hydrogel - to prevent or reduce the first steps of the FBR: plasma protein adsorption and cell adhesion to the interface. Synthesis and characterization of the SBMA hydrogel was done. Preliminary biocompatibility analysis of the zwitterionic hydrogel, using hydrogel-conditioned medium, showed no cytotoxicity at all vs. control. We seeded GFP-labelled human myofibroblasts on PEG- and SBMA hydrogel-coated polyimide surfaces and evaluated their adhesion and cell viability at different time-points. Because of the high hydration, low stiffness reflecting the one of neural tissue, and ultra-low fouling characteristics of the SBMA hydrogel, this polymer showed lower myofibroblast adhesion and different cell morphology compared to adhesion controls, thereby representing a better coating than PEG for potentially mitigating the FBR. We conclude that soft SBMA hydrogels could outperform PEG coatings in vitro as more suitable dressings of intraneural electrodes. Furthermore, such SBMA-based antifouling materials can be envisioned as long-term diffusion-based delivery systems for controlled release of anti-inflammatory and anti-fibrotic drugs in vivo

The incidence of comminuted proximal femur fractures is increasing, due to the growing proportion of elderly people in the general population. Severely depleted cancellous bone in the femoral head and neck prevent stable proximal purchase, mandatory for intertrochanteric and subtrochanteric fractures. Osteoporotic bones are associated with high implant failure rates, evidenced by cutout and upward screw penetration of the hip joint. A new method for femoral head fixation is described. The peg consists of a distal end that can expand in diameter from 7.8mm to 10.5mm by using pressurized saline, allowing good abutment into the femoral head. The peg may be connected to a side plate or an intramedullary device for inter or subtrochanteric fractures. Materials and Methods: Ten femoral heads were retrieved from patients who underwent hip hemiarthroplasty due to subcapital fracture. The heads were covered with a transparent epoxy resin until full solidification was obtained. An 8mm drill-hole was used to drill from the distal femoral neck along the femoral head axis, not penetrating the subchondral bone and cartilage. Afterwards, 1.4mm drill was used to penetrate the cartilage and subchondral bone of the femoral head for insertion of a pressure gage. Intraosseous pressure measurements were then recorded. The peri-prosthetic bone density was evaluated by Dual Energy X-ray Absorptiometry (DEXA) and Microradiography Computer Analysis in two stages: 1) with the peg unexpanded, and 2) with the peg expanded. In addition, Instron 8871 tested axial load, pullout and rotatory strengths of the peg. Results: Increased periprosthetic bone density following peg expansion was demonstrated on DEXA and microradiography with no increase in the intraosseous pressure. The friction coefficient of the bone implant interface, calculated by axial load measurements, was less than the coefficient of steel to steel. Pullout and rotatory strengths were as good as those reported for the Dynamic Hip Screw (DHS). Conclusions: Bone stock preservation due to compression of the depleted cancellous bone (rather than removed bone by drilling) may improve the mechanical properties of the periprosthetic bone and the stability of the fixation. Due to the strong abutment of the peg, hardware failure, mainly bone cutout can be reduced. Due to its lower friction coefficient, the hip peg will begin to slide following axial load through the plate or the intramedullary device, rather than penetrating the femoral head. Preliminary positive results indicate that this new method may be suitable for inter or subtrochanteric femoral fracture fixation

Aim of the study: To prove that tapered pegs are effective in reducing tibial tray subsidence in vitro and that this effect is related to the dimensions of these pegs. Methods: The peg designs were drawn up mathematically to allow for a unified surface area – Three different designs were used. The pegs were made from cobalt chrome, were conical in shape with a cut off tip and had a variable base and height and an equal surface area. These pegs were fixed with screws to an IB 11 HA coated tibial tray. Wet foam was used as bone substitute, this is an open cell foam that is fairly fragile but has the benefit of being constant and is cheap and readily available. This foam is not desired to have cancellous bone characteristics but is useful in observing the relative effect of adding these pegs. Two different settings in vivo were mimicked: that of a tibial tray and pegs resting fully on cancellous bone, in which case a central vertical force was applied, and that of the tray resting on the cortex on one side with a lateral vertical force applied over the other side in both the proud and flush setting (2& 4 pegs respectively). The investigation was undertaken using a home made system allowing a crude estimate of the forces producing initial subsidence, which was identified by initial fracture of the foam, and total subsidence which was identified as total failure of the foam. Each test was carried out three times. Controls were carried out on the tray with no pegs and on the pegs individually before attaching these to the tray and repeating the tests for each design. Results: Using this crude approach, the mean control force for total subsidence of the pegs was as follows: Short with wide base 550.3 g (± 45.3 g), medium length and base 475.6 g (± 24.25 g), long with narrow base 364.5 g (± 24.25 g). The mean control force for initial subsidence of the tray without pegs when subjected to a vertical central force was 4.3 kg (4–4.5 ± 0.27 kg) and the total subsidence force for the tray was 7.32 Kg (5.5–8, ± 0.84 kg). The mean central vertical force for initial subsidence of the tray with the tapers mounted was 7.16 kg (7–7.5 ± 0.28), for the short wide pegs, 5.33 kg (5–5.5 ± 0.28) for the medium pegs and 5.33 kg (5–6 ± 0.57) for the long pegs. The mean central vertical force for total subsidence of the tray with the tapers mounted was 9 kg (8.5–9.5 ± 0.5) for the short wide pegs, 9.8 kg (8–11 ± 1.6) for the medium pegs and 9.6 kg (8.5–11.5 ± 1.6) for the long pegs. The mean lateral control force for total subsidence of the proud tray with pegs resting on the wooden ledge was 5 kg (4–6 ± 0.75). The mean lateral vertical force for total subsidence with all pegs mounted was 7.16 kg (7–7.5 ± 0.28) for the short pegs, 5.8 kg (5.5–6 ± 0.28) for the medium pegs and 5.5 (5.5–5.6 ± 0.05) for the long pegs. No definite initial subsidence force could be identified. The mean lateral control force for total subsidence of the flush tray resting on the wooden ledge was 13.16 kg (12.5–14 ± 0.76). The mean lateral vertical force for total subsidence with pegs mounted on the foam side was 12.3 kg (11.5–13 ± 0–76) for the short pegs, 13.5 kg (12–15.5 ± 1.8) for the medium pegs and 13.83 kg (12–15.5 ± 1.7) for the long pegs. Again no definite initial subsidence force could be identified. Conclusion: The addition of tapered conical pegs to the tibial tray increases the resistance to subsidence when subjected to a central vertical force with the tray sitting fully on foam. The initial subsidence resistance was more marked in the case of the short wide variety. In the case of the tray resting on the hard edge and a lateral force applied, the proud tray showed improved resistance to total subsidence with the short pegs while the flush tray did not show improvement with pegs and was marginally worse with the short pegs. This is probably due to a higher margin of observer error

Purposes of the study. The most common fracture of the cervical spine in the elderly population is a fracture of the odontoid peg. Such fractures are usually not displaced and these are commonly treated non-operatively. Rarely though, peg fractures are displaced and then their management is less straightforward. This is in part because the group of patients who sustain them frequently have complex and pre-existing medical co-morbidities and in part because a new neurological injury may have been sustained as a result of the peg fracture itself. Many options for the management of displaced peg fractures, both operative and non-operative have been described in the literature and discussion continues as to which technique is superior and in which patient population. The purpose of this study was to follow-up those patients who were managed operatively in our unit between 2007 and 2009. Methods and Results. We present our case series of 4 patients who sustained significantly displaced fractures of the odontoid peg with accompanying neurological injury, who were treated with posterior stabilisation using the Harms technique. Conclusions. We have found this method to be safe and reliable. It not only yields a good surgical outcome, but allows patients' rehabilitation to be optimised, maximising functional improvement. We believe the technique is superior to anterior stabilisation in this patient population because it utilises superior posterior bone quality and mechanical fixation. The approach in our unit is to treat elderly patients with displaced odontoid peg fractures according to the same principles as would be followed in managing those that have disabling injuries such as fractures of the femoral neck; early stabilisation and early mobilisation in those patients whose co-morbidities allow it

Background. Fractures of the odontoid peg are one of the commonest spinal injuries in the elderly population. In this population there is a higher risk of morbidity and mortality as a result of the injury. The magnitude of this risk has not been quantified in the literature. Aim. To show a survivorship analysis in a cohort of elderly patients with odontoid peg fractures. Method and Materials. A 6-year retrospective analysis was performed on all patients >65 years old admitted to a spinal unit with an isolated odontoid peg fracture. Actuarial (Life-Table) analysis was used to estimate survivorship from the date of fracture. Results. A total of 32 patients > 65 years of age with isolated odontoid peg fractures were identified. There were 17 male and 15 female. A low velocity mechanical fall was the commonest cause for the injury. The average age for the females was 86.7 years and for the males 78 years. The age distribution was unimodal in both sex, the greatest number occurring for the females in the 85-94 year age group and 75-84 years for the males. Overall, it was estimated that only 62.5 % would be alive by one year. The period of greatest mortality was within the first 12 weeks, a lesser contribution from then to one year, and had no impact on mortality thereafter. Males appeared to suffer a heavier mortality than females within the first year. At one year the male survival rate had fallen to 58.8% compared with a female rate of 66.6%. Conclusion. We observed that odontoid peg fractures in the elderly are not benign injuries and are a cause of high mortality rates within the first three months of the injury. Patients who survived to one year following the injury were observed to have their risk return to age and sex matched rates for this population

Background. Fractures of the odontoid peg are one of the commonest cervical spinal injuries in the elderly population. In this population there is a higher risk of morbidity and mortality as a result of the injury. The magnitude of the mortality risk has not been quantified in the literature. Aim. To show a survivorship analysis in a cohort of elderly patients with odontoid peg fractures. Method & Materials. A 6-year retrospective analysis was performed on all patients >65 years old with isolated odontoid peg fracture. Kaplan-Meir curve was used to estimate survivorship from the date of fracture. Results. A total of 32 patients witha mean age of 82.1 years were analysed. There were 17 male and 15 female with an average follow-up of 20.4 months. A low velocity mechanical fall was the commonest cause for the injury in 93.7% of cases. 81% of cases were treated with rigid collar immobilsation. Overall, it was estimated that only 62.5 % would be alive by one year. The period of greatest mortality was within the first 12 weeks, a lesser contribution from then to one year, and had no impact on mortality thereafter. Multivariate logistic regression demonstrated that age (P= 0.02) was significant factor with an odds ratio of 1.2. There was no significant relationship among gender or treatment with the occurrence of an adverse event. Conclusion. We observed a 3 month and one year mortality rates of 255 and 37.5% respectively. Odontoid peg fractures in the elderly are not benign injuries and are a cause of high mortality rates within the first three months of the injury. Patients who survived to one year following the injury were observed to have their risk return to age and sex matched rates for this population

This is a study of the quality of outcome of the first 100 patients who received the Twin Peg Oxford Partial knee replacement; which has been designed with a 15 degree extra surface for contact in deep flexion, and two pins for more secure fixation. We measured the outcome in patients with anteromedial osteoarthritis at 2 years after implantation using patient perception outcome measures: the OKS (Oxford Knee Score) and a patient satisfaction questionnaire. We also measured range of motion, the AKS (American Knee Society Score-Objective), the AFS (American Knee Society Score-Functional), and carried out a radiological assessment. The results showed a mean OKS of 41, a mean AKS of 93, a mean AFS of 84, a mean range of motion of 130 degrees and a 97% satisfaction rate. Results were significantly better in male patients. There were no deaths, infections, dislocations, fractures or revisions. There were no radiolucent lines of 2 mms or more at the femoral bone-cement interfaces. The introduction of this new version of the Oxford knee shows excellent clinical and radiological results which are at least as good as those seen with the Phase 3 Oxford Partial knee replacement. Small adjustments were made to the minimally invasive approach: a reduced invasive incision for ease of implantation. For those surgeons who are concerned over the risks of femoral loosening with the Phase 3 implant, or desire an improved surface area of contact at high angles of flexion, this Twin Peg Oxford Partial knee replacement offers an excellent alternative

The introduction of a trabecular tantalum rod has been proposed for the management of early-stage osteonecrosis of the femoral head but serves as a single-point of support of the necrotic lesion. We describe a technique using two or three 4.2 mm (or later 4.7 mm) tantalum pegs for the prevention of collapse of the necrotic lesion. We prospectively studied 21 patients (26 hips) with non-traumatic osteonecrosis of the femoral head treated in this manner. Of these, 21 patients (24 hips) were available for radiological and clinical evaluation at a mean follow-up of 46 months (18 to 67). Radiological assessment showed that only eight hips deteriorated according to the Association Research Circulation Osseous classification, and four hips according to the Classification of the Japanese Investigation Committee of Health and Welfare. Functional improvement was obtained with an improvement in the mean Harris hip score from 65.2 (33.67 to 95) to 88.1 (51.72 to 100), the mean Merle D’Aubigné-Postel score from 13 (6 to 18) to 16 (11 to 18), a mean visual analogue score for pain from 5.2 (0 to 9.5) to 2.6 (0 to 7), and the mean Short-Form 36 score from 80.4 (56.8 to 107.1) to 92.4 (67.5 to 115.7). Of these 24 hips followed for a minimum of 18 months, three were considered as failures at the final follow-up, having required total hip replacement. One of the hips without full follow-up was also considered to be a failure. In more than two-thirds of the surviving hips a satisfactory clinical outcome was achieved with promising radiological findings. The estimated mean implant survival was 60 months (95% confidence interval 53.7 to 66.3)

The management of type two odontoid peg fractures remains controversial. The policy in our unit is to initially manage all of these injuries non-operatively. Patients with displaced fractures (0.2mm translation, > 15° angulation) are placed in halo vests followed by fracture reduction under radiological control. Undisplaced or minimally displaced fractures are treated in either custom-made minerva orthoses or halo vests. We report the results of 42 consecutive cases of type two odontoid peg fractures. There were 24 males and 18 females with a mean age of 53 (range 18–89) years. Twenty-one (50%) of patients were > 65 years of age. In 29 cases the fracture was undisplaced or minimally displaced and in the remaining 13 cases it was displaced (> 2mm translation, > 15° angulation) either posteriorly (extension-type)(6) or anteriorly (flexion type) (7). All displaced cases were treated in halo vests while the remainder were treated in minervas (14) or halo vests (15). Loss of reduction occurred in nine cases necessitating adjustment in five and C1/2 posterior fusion in four. Of these cases five were displaced extension type-fractures, two required fusion. Pin site infection necessitated early removal of halo vest and conversion to minerva in three cases. In all of these cases fracture union was achieved. Overall, union was achieved in 37 patients giving a non-union rate of 12%. The mean age of the five non-unions was 42 years with only one patient over 65 years of age. Four of these patients had C1/2 posterior fusions and the remaining patient refused surgery. Of the 29 patients with displaced or minimally displaced fractures five (17%) required surgery for either non-union (3) or displacement (2), whereas three (23%) of the displaced group required surgery for non-union (1) or displacement (2). All of these were extension type fractures. We conclude that a policy of non-operative management of these fractures resulted in union in a high proportion of patients of all age groups except for those with extension type fractures. This fracture pattern may warrant primary surgical intervention

We have treated osteochondral lesions of the talus using cortical bone pegs. We examined 27 ankles (27 patients) after a mean follow-up of 7.0 years (2 to 18.8). The mean age of the patients was 27.8 years (12 to 62). An unstable osteochondral fragment or osteosclerotic changes in the bed of the talus were regarded as indications for the procedure. The clinical results were good in 24 ankles (89%) and fair in three (11%); none had a poor result. There was also radiological improvement in 24 ankles. Repair of the articular surface and stability of the lesion can be achieved even in unstable chronic lesions

Background: Type II odontoid fractures are the commonest upper cervical spine injury in the elderly, following minor falls. Structural heterogeneity within the axis with deficiency of bone mass in the base of the odontoid process has been attributed for these fractures. Aims: To analyse whether osteoporosis at the dens-body junction is directly related to the occurrence of odontoid fractures in the elderly. Material and Methods: We studied the reformatted CT scan images of 36 patients over the age of 70 years who had cervical spine injuries following minor trauma. In all these patients the severity of osteoporosis at the dens-body junction, and in the peg and body of axis were evaluated. The severity was graded into none, mild, moderate and severe, depending on the cortical thickness, trabecular pattern, and the size of holes (absence of trabeculae) using sagittal, coronal and transverse sections of CT scan pictures. The osteoporosis was graded into none, mild, moderate and severe. Statistical analysis was performed using Pearsons Chi-square test to find the significance of osteoporosis at the dens-body junction in producing Type II odontoid fractures in the elderly. Results: Type II odontoid fractures was seen in 21 patients. Eleven of the 21 patients with Type II fractures and eight of the 15 patients with no Type II odontoid fractures had significant osteoporosis at the dens-body junction. Five patients with Type II fracture and eight patients with no Type II fractures had significant osteoporosis at the dens and body of axis. Statistical analysis showed that the osteoporosis at the dens-body junction was not significant in patients with Type II odontoid fracture compared to those with no Type II odontoid fracture (Chi-square value = 1.1; df = 3, p = 0.78). Conclusions: Eventhough osteoporosis is one of the factors that increase the incidence of Type II fractures of the odontoid process in the elderly, it is not a direct aetiological factor

Purpose: The goal was to determine whether locking screws (LS) or smooth locking pegs (SP), optimize fixation of 4-part intraarticular distal radius fractures. The secondary goal was to determine which combinations of LS and SP influence construct stability. Method: In anatomic radius models, 4-part intraarticular distal radius fractures were fixed using volar locking plates. For the first part, 16 specimens were randomized to receive either 2 LS or 2 SP in each of the 3 pairs of holes in the plate. For the second part, 30 specimens were randomized to receive any 4 combinations of LS and SP in each of the 3 pairs of holes. Axial loading to failure was applied. Results: Constructs consisting of 4 SP within the lunate fragment were significantly weaker than constructs with 4 LS (mean 626.18 N vs. mean 980.76 N, p=0.01283). Constructs with SP in the ulnar positions of the lunate fragment were weaker than with LS in these positions (mean 736.73 N vs. 977.37 N respectively, p=0.00866). LS in the subchondral position of the lunate fragment were stronger than SP in these positions (mean 1226.99 N vs. 933.64 N, p= 0.00468) and any other combination (mean 1226.99 N vs. 941.97 N, p=0.0027). Conclusion: The use of LS as opposed to SP for 4-part intraarticular distal radius fractures, particularly subchondral and in ulnar side of the lunate fragment, optimizes construct stability. This may have implications on postoperative rehabilitation protocols and may limit costs related to the use of volar locking plates

In a prospective study between 2000 and 2005, 22 patients with primary osteoarthritis of the shoulder had a total shoulder arthroplasty with a standard five-pegged glenoid component, 12 with non-offset humeral head and ten with offset humeral head components. Over a period of 24 months the relative movement of the glenoid component with respect to the scapula was measured using radiostereometric analysis.

Nine glenoids needed reaming for erosion. There was a significant increase in rotation about all three axes with time (p < 0.001), the largest occurring about the longitudinal axis (anteversion-retroversion), with mean values of 3.8° and 1.9° for the non-offset and offset humeral head eroded subgroups, respectively. There was also a significant difference in rotation about the anteversion-retroversion axis (p = 0.01) and the varus-valgus (p < 0.001) z-axis between the two groups. The offset humeral head group reached a plateau at early follow-up with rotation about the z-axis, whereas the mean of the non-offset humeral head group at 24 months was three times greater than that of the offset group accounting for the highly significant difference between them.