Concerns have been raised that deformation of acetabular shells may disrupt the assembly process of modular prostheses. In this study we aimed to examine the effect that the strength of bone has on the amount of deformation of the acetabular shell. The hypothesis was that stronger bone would result in greater deformation. A total of 17 acetabular shells were inserted into the acetabula of eight cadavers, and deformation was measured using an optical measuring system. Cores of bone from the femoral head were taken from each cadaver and compressed using a materials testing machine. The highest peak modulus and yield stress for each cadaver were used to represent the strength of the bone and compared with the values for the deformation and the surgeon’s subjective assessment of the hardness of the bone. The mean deformation of the shell was 129 µm (3 to 340). No correlation was found between deformation and either the maximum peak modulus (r² = 0.011, t = 0.426, p = 0.676) or the yield stress (r² = 0.024, t = 0.614, p = 0.549) of the bone. Although no correlation was found between the strength of the bone and deformation, the values for the deformation observed could be sufficient to disrupt the assembly process of modular acetabular components. Cite this article: Bone Joint J 2015; 97-B:473–7

The purposes of this study were to define the range of laxity of the interosseous ligaments in cadaveric wrists and to determine whether this correlated with age, the morphology of the lunate, the scapholunate (SL) gap or the SL angle. We evaluated 83 fresh-frozen cadaveric wrists and recorded the SL gap and SL angle. Standard arthroscopy of the wrist was then performed and the grades of laxity of the scapholunate interosseous ligament (SLIL) and the lunotriquetral interosseous ligament (LTIL) and the morphology of the lunate were recorded. Arthroscopic evaluation of the SLIL revealed four (5%) grade I specimens, 28 (34%) grade II, 40 (48%) grade III and 11 (13%) grade IV. Evaluation of the LTIL showed 17 (20%) grade I specimens, 40 (48%) grade II, 28 (30%) grade III and one (1%) grade IV. On both bivariate and multivariate analysis, the grade of both the SLIL and LTIL increased with age, but decreased with female gender. The grades of SLIL or LTIL did not correlate with the morphology of the lunate, the SL gap or the SL angle. The physiological range of laxity at the SL and lunotriquetral joints is wider than originally described. The intercarpal ligaments demonstrate an age-related progression of laxity of the SL and lunotriquetral joints. There is no correlation between the grades of laxity of the SLIL or LTIL and the morphology of the lunate, the SL gap or the SL grade. Based on our results, we believe that the Geissler classification has a role in describing intercarpal laxity, but if used alone it cannot adequately diagnose pathological instability. We suggest a modified classification with a mechanism that may distinguish physiological laxity from pathological instability

The aim of this study was to establish a classification system for the acromioclavicular joint using cadaveric dissection and radiological analyses of both reformatted computed tomographic scans and conventional radiographs centred on the joint. This classification should be useful for planning arthroscopic procedures or introducing a needle and in prospective studies of biomechanical stresses across the joint which may be associated with the development of joint pathology. We have demonstrated three main three-dimensional morphological groups namely flat, oblique and curved, on both cadaveric examination and radiological assessment. These groups were recognised in both the coronal and axial planes and were independent of age

The purpose of this study was to determine whether it would be feasible to use oblique lumbar interbody fixation for patients with degenerative lumbar disease who required a fusion but did not have a spondylolisthesis. A series of CT digital images from 60 patients with abdominal disease were reconstructed in three dimensions (3D) using Mimics v10.01: a digital cylinder was superimposed on the reconstructed image to simulate the position of an interbody screw. The optimal entry point of the screw and measurements of its trajectory were recorded. Next, 26 cadaveric specimens were subjected to oblique lumbar interbody fixation on the basis of the measurements derived from the imaging studies. These were then compared with measurements derived directly from the cadaveric vertebrae. Our study suggested that it is easy to insert the screws for L1/2, L2/3 and L3/4 fixation: there was no significant difference in measurements between those of the 3-D digital images and the cadaveric specimens. For L4/5 fixation, part of L5 inferior articular process had to be removed to achieve the optimal trajectory of the screw. For L5/S1 fixation, the screw heads were blocked by iliac bone: consequently, the interior oblique angle of the cadaveric specimens was less than that seen in the 3D digital images. . We suggest that CT scans should be carried out pre-operatively if this procedure is to be adopted in clinical practice. This will assist in determining the feasibility of the procedure and will provide accurate information to assist introduction of the screws. Cite this article: Bone Joint J 2013;95-B:977–82

We describe a 63-year-old man who had xanthomatosis of the right tendo Achillis. He had undergone excision of the left tendo Achillis 17 years earlier without reconstruction for the same condition. The neurological history and examination were normal. Blood investigations showed hypercholestrolaemia, for which he was being treated with statins. He was referred with pain in the right tendo Achillis and problems with footwear. He was treated by excision of the right tendo Achillis, the xanthomatous nodules and the involved skin, followed by reconstruction with a cadaver bone-tendon graft. At follow-up eight months postoperatively, the scar had healed well. He walked without pain and could wear any type of shoe. Plain radiographs showed that the bone graft had healed. The American Orthopaedic Foot and Ankle Society hindfoot score was 95/100. The patient’s subjective evaluation of the result was very good

Damage to the cartilage of the distal radioulnar joint frequently leads to pain and limitation of movement, therefore repair of this joint cartilage would be highly desirable. The purpose of this study was to investigate the fixation of scaffold in cartilage defects of this joint as part of matrix-assisted regenerative autologous cartilage techniques. Two techniques of fixation of collagen scaffolds, one involving fibrin glue alone and one with fibrin glue and sutures, were compared in artificially created cartilage defects of the distal radioulnar joint in a human cadaver. After being subjected to continuous passive rotation, the methods of fixation were evaluated for cover of the defect and pull out force. No statistically significant differences were found between the two techniques for either cover of the defect or integrity of the scaffold. However, a significantly increased mean pull out force was found for the combined procedure, 0.665 N (0.150 to 1.160) versus 0.242 N (0.060 to 0.730) for glue fixation (p = 0.001). This suggests that although successful fixation of a collagen type I/III scaffold in a distal radioulnar joint cartilage defect is feasible with both forms of fixation, fixation with glue and sutures is preferable. Cite this article: Bone Joint J 2014;96-B:508–12

The joint surfaces of 60 hips obtained from the cadavers of elderly Asians were studied to determine the incidence, the grade and the distribution of both non-progressive (age-related) and progressive degenerative changes. It was observed that in the Asian population of 40 to 90 years of age, non-progressive changes were common, being seen in 66% of the acetabular specimens and 50% of the femoral heads. Only one specimen of the 60 showed unexplained progressive degenerative change. We conclude that primary osteoarthritis of the hip is rare in Asians

The purpose of the work described was to find the average pressure on each of several areas of the acetabular cartilage of the cadaver hip under physiological loads. By obtaining load-deflection curves for one chosen area of cartilage, firstly with all the cartilage present and then after the successive removal of other areas, the fractions of the original load carried by the several areas were found, and hence the average pressures on those areas. Seventeen hips (age range twenty. two to eighty-seven years) were examined. Local pressures varied from zero to 3.4 times the average pressure in each hip. The highest pressures in the series (about 4 to 5 megaNewtons per square metre) were on areas of thin fibrocartilage which were identified at the zenith of certain acetabula. The results are too few to establish whether or not the pressure distribution was age-related. The higher pressures found are within the range which in other experiments has led to fatigue failure of femoral head cartilage, and it is suggested that hips in which such pressures exist under loads of three times body weight may be predisposed to osteoarthritis

The fourth lumbar vertebrae and L4-5 discs from six cadaveric lumbar spines were subjected to detailed strain gauge analysis under conditions of controlled loading. With central compression loads, maximal compressive strain was found to occur near the bases of the pedicles and on both superficial and deep surfaces of the pars interarticularis, which emphasises the importance of the posterior elements of lumbar vertebrae in transmitting load. Radial bulge and tangential strain of the disc wall were maximal at the posterolateral surface, in agreement with the fact that disc degeneration and prolapse commonly occur there. Under posterior offset loads simulating extension, both compressive and tensile strains were found to be increased on both surfaces of the pars interarticularis, which suggests that hyperextension may lead to stress fractures and spondylolisthesis. Posterior offset loads also increased the radial bulge of the posterior disc wall and tangential strain at the anterior surface of the disc. Anterior offset loads simulating flexion increased the radial bulge of the anterior disc wall and tangential strain at the posterior surface of the disc. These findings are compatible with movement of the nucleus pulposus within the disc during flexion and extension. This hypothesis was supported by post-mortem discography

We studied five cadaver shoulders to determine the strength relationship of the four rotator cuff muscles. The mean fibre length and volume of each muscle were measured, from which the physiological cross-sectional area was calculated. This value was used to estimate the force which each muscle was capable of generating. The lever arm of each muscle about the humeral head was then measured and the moment exerted was calculated. The strength ratios between the muscles were more or less constant in the five specimens. Subscapularis was the most powerful muscle and contributed 53% of the cuff moment; supraspinatus contributed 14%, infraspinatus 22% and teres minor 10%. The force-generating capacity of the subscapularis was equal to that of the other three muscles combined

Six normal cadaver lower limbs were mounted on a specially designed loading apparatus. Wires were used to simulate the five muscle bellies of the quadriceps, the ratio of their tensions having been determined from that of the anatomical cross-sectional areas of the muscles. A three-camera system was used to track the patella during knee movements from flexion to extension. The patellofemoral contact area was determined by pressure-sensitive film. The limb was loaded with and without tension on the wire which simulated the oblique part of the vastus medialis (VMO). Absence of VMO tension caused the patella to displace laterally (4.2 mm) and increased the load on the lateral patellar facet throughout the range of knee motion. When the tension on the wire simulating vastus lateralis was reduced by 40% to simulate the effect of a lateral release procedure, the abnormal kinematics caused by the absent VMO returned to normal

A method for direct measurement of the local pressures in the acetabular cartilage is described. Pressure transducers were introduced into the subchondral bone and positioned there in contrast with the cartilage: the transducers were calibrated in situ. Twelve cadaveric hips were prepared in this way and the pressures were measured with the joint loaded in flexion, extension, abduction, adduction, and in lateral and medial rotation. The highest pressures were recorded in the anterior and posterior segments of the acetabulum; the lowest pressures were constantly found at the zenith of the joint. The relationship of these findings to the pathogenesis of osteoarthritis is considered

Using 26 cadaver shoulders, we produced a standard defect in the supraspinatus tendon and performed one of three types of repair. Their strength was found by testing in tension the force required to produce a gap of 3 mm, then 6 mm, and finally total disruption of the repair. The use of a polyethylene patch to spread the forces over the lateral bone surface and of extra sutures to grasp the tendon end raised by 2.6 times the load at which a 3 mm gap in the repair occurred and by 1.7 times the load to failure

We studied the arterial anatomy and the effect of four-part fractures on the vascularity of the humeral head, using barium sulphate perfusion of 16 cadaver shoulders. The main arterial supply to the humeral head was via the ascending branch of the anterior humeral circumflex artery and its intraosseous continuation, the arcuate artery. There were significant intraosseous anastomoses between the arcuate artery and: 1) the posterior humeral circumflex artery through vessels entering the posteromedial aspect of the proximal humerus; 2) metaphyseal vessels; and 3) the vessels of the greater and lesser tuberosities. Simulated four-part fractures prevented the perfusion of the humeral head in most cases. If, however, the head fragment extends distally below the articular surface medially, some perfusion of the head persists by the posteromedial vessels. These vessels are important in the management of comminuted fractures of the proximal humerus

In six unloaded cadaver knees we used MRI to determine the shapes of the articular surfaces and their relative movements. These were confirmed by dissection. Medially, the femoral condyle in sagittal section is composed of the arcs of two circles and that of the tibia of two angled flats. The anterior facets articulate in extension. At about 20° the femur ‘rocks’ to articulate through the posterior facets. The medial femoral condyle does not move anteroposteriorly with flexion to 110°. Laterally, the femoral condyle is composed entirely, or almost entirely, of a single circular facet similar in radius and arc to the posterior medial facet. The tibia is roughly flat. The femur tends to roll backwards with flexion. The combination during flexion of no antero-posterior movement medially (i.e., sliding) and backward rolling (combined with sliding) laterally equates to internal rotation of the tibia around a medial axis with flexion. About 5° of this rotation may be obligatory from 0° to 10° flexion; thereafter little rotation occurs to at least 45°. Total rotation at 110° is about 20°, most if not all of which can be suppressed by applying external rotation to the tibia at 90°

Aims. Surgical approaches that claim to be minimally invasive, such as the direct anterior approach (DAA), are reported to have a clinical advantage, but are technically challenging and may create more injury to the soft-tissues during joint exposure. Our aim was to quantify the effect of soft-tissue releases on the joint torque and femoral mobility during joint exposure for hip resurfacing performed via the DAA. Methods. Nine fresh-frozen hip joints from five pelvis to mid-tibia cadaveric specimens were approached using the DAA. A custom fixture consisting of a six-axis force/torque sensor and motion sensor was attached to tibial diaphysis to measure manually applied torques and joint angles by the surgeon. Following dislocation, the torques generated to visualize the acetabulum and proximal femur were assessed after sequential release of the joint capsule and short external rotators. Results. Following initial exposure, the ischiofemoral ligament (7 to 8 o’clock) was the largest restrictor of exposure of the acetabulum, contributing to a mean 25% of overall external rotational restraint. The ischiofemoral ligament (10 to 12 o’clock) was the largest restrictor of exposure of the proximal femur, contributing to 25% of overall extension restraint. Releasing the short external rotators had minimal contribution in torque generated during joint exposure (≤ 5%). Conclusion. Adequate exposure of both proximal femur and acetabulum may be achieved with minimal torque by performing a full proximal circumferential capsulotomy while preserving short external rotators. The joint torque generated and exposure achieved is dependent on patient factors; therefore, some cases may necessitate further releases. Cite this article: Bone Joint J 2024;106-B(3 Supple A):59–66

Aims. The survival of humeral hemiarthroplasties in patients with relatively intact glenoid cartilage could theoretically be extended by minimizing the associated postoperative glenoid erosion. Ceramic has gained attention as an alternative to metal as a material for hemiarthroplasties because of its superior tribological properties. The aim of this study was to assess the in vitro wear performance of ceramic and metal humeral hemiarthroplasties on natural glenoids. Methods. Intact right cadaveric shoulders from donors aged between 50 and 65 years were assigned to a ceramic group (n = 8, four male cadavers) and a metal group (n = 9, four male cadavers). A dedicated shoulder wear simulator was used to simulate daily activity by replicating the relevant joint motion and loading profiles. During testing, the joint was kept lubricated with diluted calf serum at room temperature. Each test of wear was performed for 500,000 cycles at 1.2 Hz. At intervals of 125,000 cycles, micro-CT scans of each glenoid were taken to characterize and quantify glenoid wear by calculating the change in the thickness of its articular cartilage. Results. At the completion of the wear test, the total thickness of the cartilage had significantly decreased in both the ceramic and metal groups, by 27% (p = 0.019) and 29% (p = 0.008), respectively. However, the differences between the two were not significant (p = 0.606) and the patterns of wear in the specimens were unpredictable. No significant correlation was found between cartilage wear and various factors, including age, sex, the size of the humeral head, joint mismatch, the thickness of the native cartilage, and the surface roughness (all p > 0.05). Conclusion. Although ceramic has better tribological properties than metal, we did not find evidence that its use in hemiarthroplasty of the shoulder in patients with healthy cartilage is a better alternative than conventional metal humeral heads. Cite this article: Bone Joint J 2024;106-B(11):1273–1283

Aims. The aim of the study was to investigate whether the primary stability of press-fit acetabular components can be improved by altering the impaction procedure. Methods. Three impaction procedures were used to implant acetabular components into human cadaveric acetabula using a powered impaction device. An impaction frequency of 1 Hz until complete component seating served as reference. Overimpaction was simulated by adding ten strokes after complete component seating. High-frequency implantation was performed at 6 Hz. The lever-out moment of the acetabular components was used as measure for primary stability. Permanent bone deformation was assessed by comparison of double micro-CT (µCT) measurements before and after impaction. Acetabular component deformation and impaction forces were recorded, and the extent of bone-implant contact was determined from 3D laser scans. Results. Overimpaction reduced primary acetabular component stability (p = 0.038) but did not significantly increase strain release after implantation (p = 0.117) or plastic deformations (p = 0.193). Higher press-fits were associated with larger polar gaps for the 1 Hz reference impaction (p = 0.002, R. 2. = 0.77), with a similar trend for overimpaction (p = 0.082, R. 2. = 0.31). High-frequency impaction did not significantly increase primary stability (p = 0.170) at lower impaction forces (p = 0.001); it was associated with smaller plastic deformations (p = 0.035, R. 2. = 0.34) and a trend for increased acetabular component relaxation between strokes (p = 0.112). Higher press-fit was not related to larger polar gaps for the 6 Hz impaction (p = 0.346). Conclusion. Overimpaction of press-fit acetabular components should be prevented since additional strokes can be associated with increased bone damage and reduced primary stability as shown in this study. High-frequency impaction at 6 Hz was shown to be beneficial compared with 1 Hz impaction. This benefit has to be confirmed in clinical studies. Cite this article: Bone Joint J 2023;105-B(3):261–268

Aims. The objective of this study is to assess the use of ultrasound (US) as a radiation-free imaging modality to reconstruct 3D anatomy of the knee for use in preoperative templating in knee arthroplasty. Methods. Using an US system, which is fitted with an electromagnetic (EM) tracker that is integrated into the US probe, allows 3D tracking of the probe, femur, and tibia. The raw US radiofrequency (RF) signals are acquired and, using real-time signal processing, bone boundaries are extracted. Bone boundaries and the tracking information are fused in a 3D point cloud for the femur and tibia. Using a statistical shaping model, the patient-specific surface is reconstructed by optimizing bone geometry to match the point clouds. An accuracy analysis was conducted for 17 cadavers by comparing the 3D US models with those created using CT. US scans from 15 users were compared in order to examine the effect of operator variability on the output. Results. The results revealed that the US bone models were accurate compared with the CT models (root mean squared error (RM)S: femur, 1.07 mm (SD 0.15); tibia, 1.02 mm (SD 0.13). Additionally, femoral landmarking proved to be accurate (transepicondylar axis: 1.07° (SD 0.65°); posterior condylar axis: 0.73° (SD 0.41°); distal condylar axis: 0.96° (SD 0.89°); medial anteroposterior (AP): 1.22 mm (SD 0.69); lateral AP: 1.21 mm (SD 1.02)). Tibial landmarking errors were slightly higher (posterior slope axis: 1.92° (SD 1.31°); and tubercle axis: 1.91° (SD 1.24°)). For implant sizing, 90% of the femora and 60% of the tibiae were sized correctly, while the remainder were only one size different from the required implant size. No difference was observed between moderate and skilled users. Conclusion. The 3D US bone models were proven to be closely matched compared with CT and suitable for preoperative planning. The 3D US is radiation-free and offers numerous clinical opportunities for bone visualization rapidly during clinic visits, to enable preoperative planning with implant sizing. There is potential to extend its application to 3D dynamic ligament balancing, and intraoperative registration for use with robots and navigation systems. Cite this article: Bone Joint J 2021;103-B(6 Supple A):81–86

Aims. Arthroplasty skills need to be acquired safely during training, yet operative experience is increasingly hard to acquire by trainees. Virtual reality (VR) training using headsets and motion-tracked controllers can simulate complex open procedures in a fully immersive operating theatre. The present study aimed to determine if trainees trained using VR perform better than those using conventional preparation for performing total hip arthroplasty (THA). Patients and Methods. A total of 24 surgical trainees (seven female, 17 male; mean age 29 years (28 to 31)) volunteered to participate in this observer-blinded 1:1 randomized controlled trial. They had no prior experience of anterior approach THA. Of these 24 trainees, 12 completed a six-week VR training programme in a simulation laboratory, while the other 12 received only conventional preparatory materials for learning THA. All trainees then performed a cadaveric THA, assessed independently by two hip surgeons. The primary outcome was technical and non-technical surgical performance measured by a THA-specific procedure-based assessment (PBA). Secondary outcomes were step completion measured by a task-specific checklist, error in acetabular component orientation, and procedure duration. Results. VR-trained surgeons performed at a higher level than controls, with a median PBA of Level 3a (procedure performed with minimal guidance or intervention) versus Level 2a (guidance required for most/all of the procedure or part performed). VR-trained surgeons completed 33% more key steps than controls (mean 22 (. sd. 3) vs 12 (. sd. 3)), were 12° more accurate in component orientation (mean error 4° (. sd. 6°) vs 16° (. sd. 17°)), and were 18% faster (mean 42 minutes (. sd. 7) vs 51 minutes (. sd. 9)). Conclusion. Procedural knowledge and psychomotor skills for THA learned in VR were transferred to cadaveric performance. Basic preparatory materials had limited value for trainees learning a new technique. VR training advanced trainees further up the learning curve, enabling highly precise component orientation and more efficient surgery. VR could augment traditional surgical training to improve how surgeons learn complex open procedures. Cite this article: Bone Joint J 2019;101-B:1585–1592

Aims. We compared the accuracy, operating time and radiation exposure of the introduction of iliosacral screws using O-arm/Stealth Navigation and standard fluoroscopy. Materials and Methods. Iliosacral screws were introduced percutaneously into the first sacral body (S1) of ten human cadavers, four men and six women. The mean age was 77 years (58 to 85). Screws were introduced using a standard technique into the left side of S1 using C-Arm fluoroscopy and then into the right side using O-Arm/Stealth Navigation. The radiation was measured on the surgeon by dosimeters placed under a lead thyroid shield and apron, on a finger, a hat and on the cadavers. Results. There were no neuroforaminal breaches in either group. The set-up time for the O-Arm was significantly longer than for the C-Arm, while total time for placement of the screws was significantly shorter for the O-Arm than for the C-Arm (p = 0.001). The mean absorbed radiation dose during fluoroscopy was 1063 mRad (432.5 mRad to 4150 mRad). No radiation was detected on the surgeon during fluoroscopy, or when he left the room during the use of the O-Arm. The mean radiation detected on the cadavers was significantly higher in the O-Arm group (2710 mRem standard deviation (. sd. ) 1922) than during fluoroscopy (11.9 mRem . sd 14.8). (p < 0.01). Conclusion. O-Arm/Stealth Navigation allows for faster percutaneous placement of iliosacral screws in a radiation-free environment for surgeons, albeit with the same accuracy and significantly more radiation exposure to cadavers, when compared with standard fluoroscopy. Take home message: Placement of iliosacral screws with O-Arm/Stealth Navigation can be performed safely and effectively. Cite this article: Bone Joint J 2016;98-B:696–702

Aims. The primary aim of this study was to define and quantify three new measurements to indicate the position of the greater trochanter. Secondary aims were to define ‘functional antetorsion’ as it relates to abductor function in populations both with and without torsional abnormality. Patients and Methods. Three new measurements, functional antetorsion, posterior tilt, and posterior translation of the greater trochanter, were assessed from 61 CT scans of cadaveric femurs, and their reliability determined. These measurements and their relationships were also evaluated in three groups of patients: a control group (n = 22), a ‘high-antetorsion’ group (n = 22) and a ‘low-antetorsion’ group (n = 10). Results. In the cadaver group, the mean anatomical antetorsion was 14.7° (. sd. 8.5; 0 to 36.5) and the functional antetorsion 21.5° (. sd. 8.1; 3.6 to 44.3): the posterior tilt was 73.3° (. sd. 10.8; 46.9 to 88.7) and the posterior translation 0.59 (. sd. 0.2; 0.2 to 0.9). These measurements had excellent intra and interobserver agreement with a range from 0.93 to 0.99. When the anatomical antetorsion decreased, the greater trochanter was more tilted and translated posteriorly in relation to the axis of the femoral neck, and the difference between functional and anatomical antetorsion increased. The results the three patient groups were similar to those of the cadaver group. Conclusion. The position of the greater trochanter and functional antetorsion varied with anatomical antetorsion. In the surgical management of femoral retrotorsion, subtrochanteric osteotomy can result in an excessively posterior position of the greater trochanter and an increase in functional antetorsion. Cite this article: Bone Joint J 2018;100-B:712–19

Aims. Anatomical atlases document classical safe corridors for the placement of transosseous fine wires through the calcaneum during circular frame external fixation. During this process, the posterior tibial neurovascular bundle (PTNVB) is placed at risk, though this has not been previously quantified. We describe a cadaveric study to investigate a safe technique for posterolateral to anteromedial fine wire insertion through the body of the calcaneum. Materials and Methods. A total of 20 embalmed cadaveric lower limbs were divided into two groups. Wires were inserted using two possible insertion points and at varying angles. In Group A, wires were inserted one-third along a line between the point of the heel and the tip of the lateral malleolus while in Group B, wires were inserted halfway along this line. Standard dissection techniques identified the structures at risk and the distance of wires from neurovascular structures was measured. The results from 19 limbs were subject to analysis. Results. In Group A, no wires pierced the PTNVB. Wires were inserted a median 22.3 mm (range 4.7 to 39.6) from the PTNVB; two wires (4%) passed within 5 mm. In Group B, 24 (46%) wires passed within 5 mm of the PTNVB, with 11 wires piercing it. The median distance of wires from the PTNVB was 5.5 mm (range 0 to 30). A Mann–Whitney U test showed that this was significantly closer than in Group A (Hodges–Lehmann shift, 14.06 mm; 95% confidence interval (CI) 10.52 to 16.88; p < 0.0001). In Group B, with an increased angle of insertion there was greater risk to the PTNVB (r. s.  = -0.80; p < 0.01). Conclusion. Insertion of wires using an entry point one-third along a line from the point of the heel to the tip of the lateral malleolus (Group A) appears to be the safer technique. An insertion angle of up to 30° to the coronal plane can be used without significant risk to the PTNVB. Insertion of wires halfway along a line from the point of the heel to the tip of the lateral malleolus (Group B) carried a significantly higher risk of injury to neurovascular structures and, if necessary, an angle of insertion parallel to the coronal plane should be used. Cite this article: Bone Joint J 2018;100-B:1054–9

Aims. Inadvertent soft tissue damage caused by the oscillating saw during total knee arthroplasty (TKA) occurs when the sawblade passes beyond the bony boundaries into the soft tissue. The primary objective of this study is to assess the risk of inadvertent soft tissue damage during jig-based TKA by evaluating the excursion of the oscillating saw past the bony boundaries. The second objective is the investigation of the relation between this excursion and the surgeon’s experience level. Methods. A conventional jig-based TKA procedure with medial parapatellar approach was performed on 12 cadaveric knees by three experienced surgeons and three residents. During the proximal tibial resection, the motion of the oscillating saw with respect to the tibia was recorded. The distance of the outer point of this cutting portion to the edge of the bone was defined as the excursion of the oscillating saw. The excursion of the sawblade was evaluated in six zones containing the following structures: medial collateral ligament (MCL), posteromedial corner (PMC), iliotibial band (ITB), lateral collateral ligament (LCL), popliteus tendon (PopT), and neurovascular bundle (NVB). Results. The mean 75. th. percentile value of the excursion of all cases was mean 2.8 mm (SD 2.9) for the MCL zone, mean 4.8 mm (SD 5.9) for the PMC zone, mean 3.4 mm (SD 2.0) for the ITB zone, mean 6.3 mm (SD 4.8) for the LCL zone, mean 4.9 mm (SD 5.7) for the PopT zone, and mean 6.1 mm (SD 3.9) for the NVB zone. Experienced surgeons had a significantly lower excursion than residents. Conclusion. This study showed that the oscillating saw significantly passes the edge of the bone during the tibial resection in TKA, even in experienced hands. While reported neurovascular complications in TKA are rare, direct injury to the capsule and stabilizing structures around the knee is a consequence of the use of a hand-held oscillating saw when making the tibial cut. Cite this article: Bone Joint J 2020;102-B(10):1324–1330

Aims. Dual plating of distal femoral fractures with medial and lateral implants has been performed to improve construct mechanics and alignment, in cases where isolated lateral plating would be insufficient. This may potentially compromise vascularity, paradoxically impairing healing. This study investigates effects of single versus dual plating on distal femoral vascularity. Methods. A total of eight cadaveric lower limb pairs were arbitrarily assigned to either 1) isolated lateral plating, or 2) lateral and medial plating of the distal femur, with four specimens per group. Contralateral limbs served as matched controls. Pre- and post-contrast MRI was performed to quantify signal intensity enhancement in the distal femur. Further evaluation of intraosseous vascularity was done with barium sulphate infusion with CT scan imaging. Specimens were then injected with latex medium and dissection was completed to assess extraosseous vasculature. Results. Quantitative MRI revealed a mean reduction of 21.2% (SD 1.3%) of arterial contribution in the lateral plating group and 25.4% (SD 3.2%) in the dual plating group (p = 0.051); representing a mean decrease in arterial contribution of 4.2%. The only significant difference found between both experimental groups was regionally, at the lateral aspect of the distal femur with a mean drop in arterial contribution in the lateral plating group of 18.9% (SD 2.6%) versus 24.0% (SD 3.2%) in the dual plating group (p = 0.048), representing a mean decrease in arterial contribution of 5.1%. Gross dissection revealed complete destruction of periosteal vessels underneath either medial or lateral plates in both groups. The network of genicular branches contributing to the posterior and distal femoral condyles was preserved in all specimens. A medial vascular pedicle was found dividing from the superficial femoral artery at a mean 12.7 cm (SD 1.7) proximal to the medial epicondyle and was undisrupted in the dual plating group. Conclusion. Lateral locking-plate application resulted in mean 21.2% reduction in distal femur vascularity. Addition of medial plates did not further markedly decrease vascularity. As such, the majority of the vascular insult occurred with lateral plating alone. Supplemental medially based fixation did not lead to marked devascularization of the distal femur, and should therefore be considered in the setting of comminution and poor bone stock in distal femoral fractures. Further clinical research is required to confirm the results of this study. Cite this article: Bone Joint J 2020;102-B(4):530–538

Previous studies on the anatomy of the lumbar spine have not clarified the precise relationship of the origin of the lumbar roots to their corresponding discs or their angulation to the dural sac. We studied 33 cadavers (25 formalin-preserved and eight fresh-frozen) and their radiographs to determine these details. All cadavers showed a gradual decrease in the angle of the nerve root from L1 to S1. The origin of the root was found to be below the corresponding disc for the L1 to L4 roots. In the formalin-preserved cadavers 8% of the L5 roots originated above, 64% below and 28% at the L4/L5 disc. In the fresh cadavers the values were 12.5%, 62.5% and 25%, respectively. For the S1 root 76% originated above and 24% at the L5-S1 disc in the formalin-preserved cadavers and 75% and 25%, respectively, in the fresh cadavers. A herniated disc usually compresses the root before division of the root sleeve. Thus, compression of the thecal sac before the origin of the root sleeve is common for L1 to L5 whereas compression at the root sleeve is common for S1. Our findings are of value in understanding the pathophysiology of prolapse of the disc and in preventing complications during surgery

Aims

The primary objective of this study was to develop a validated classification system for assessing iatrogenic bone trauma and soft-tissue injury during total hip arthroplasty (THA). The secondary objective was to compare macroscopic bone trauma and soft-tissues injury in conventional THA (CO THA) versus robotic arm-assisted THA (RO THA) using this classification system.

Rotator cuff pathology is the main cause of shoulder pain and dysfunction in older adults. When a rotator cuff tear involves the subscapularis tendon, the symptoms are usually more severe and the prognosis after surgery must be guarded. Isolated subscapularis tears represent 18% of all rotator cuff tears and arthroscopic repair is a good alternative primary treatment. However, when the tendon is deemed irreparable, tendon transfers are the only option for younger or high-functioning patients. The aim of this review is to describe the indications, biomechanical principles, and outcomes which have been reported for tendon transfers, which are available for the treatment of irreparable subscapularis tears.

The best tendon to be transferred remains controversial. Pectoralis major transfer was described more than 30 years ago to treat patients with failed surgery for instability of the shoulder. It has subsequently been used extensively to manage irreparable subscapularis tendon tears in many clinical settings. Although pectoralis major reproduces the position and orientation of the subscapularis in the coronal plane, its position in the axial plane – anterior to the rib cage – is clearly different and does not allow it to function as an ideal transfer. Consistent relief of pain and moderate recovery of strength and function have been reported following the use of this transfer. In an attempt to improve on these results, latissimus dorsi tendon transfer was proposed as an alternative and the technique has evolved from an open to an arthroscopic procedure. Satisfactory relief of pain and improvements in functional shoulder scores have recently been reported following its use. Both pectoralis minor and upper trapezius transfers have also been used in these patients, but the outcomes that have been reported do not support their widespread use.

Cite this article: Bone Joint J 2024;106-B(9):970–977.

Aims

Acute and chronic injuries of the interosseus membrane can result in longitudinal instability of the forearm. Reconstruction of the central band of the interosseus membrane can help to restore biomechanical stability. Different methods have been used to reconstruct the central band, including tendon grafts, bone-ligament-bone grafts, and synthetic grafts. This Idea, Development, Exploration, Assessment, and Long-term (IDEAL) phase 1 study aims to review the clinical results of reconstruction using a synthetic braided cross-linked graft secured at either end with an Endobutton to restore the force balance between the bones of the forearm.

Aims

The aim of this study was to evaluate the kinematics of the elbow following increasing length of the radius with implantation of radial head arthroplasties (RHAs) using dynamic radiostereometry (dRSA).

Despite being one of the most common injuries around the elbow, the optimal treatment of olecranon fractures is far from established and stimulates debate among both general orthopaedic trauma surgeons and upper limb specialists. It is almost universally accepted that stable non-displaced fractures can be safely treated nonoperatively with minimal specialist input. Internal fixation is recommended for the vast majority of displaced fractures, with a range of techniques and implants to choose from. However, there is concern regarding the complication rates, largely related to symptomatic metalwork resulting in high rates of implant removal. As the number of elderly patients sustaining these injuries increases, we are becoming more aware of the issues associated with fixation in osteoporotic bone and the often fragile soft-tissue envelope in this group. Given this, there is evidence to support an increasing role for nonoperative management in this high-risk demographic group, even in those presenting with displaced and/or multifragmentary fracture patterns. This review summarizes the available literature to date, focusing predominantly on the management techniques and available implants for stable fractures of the olecranon. It also offers some insights into the potential avenues for future research, in the hope of addressing some of the pertinent questions that remain unanswered.

Cite this article: Bone Joint J 2023;105-B(2):112–123.

Aims. The hip’s capsular ligaments passively restrain extreme range of movement (ROM) by wrapping around the native femoral head/neck. We determined the effect of hip resurfacing arthroplasty (HRA), dual-mobility total hip arthroplasty (DM-THA), conventional THA, and surgical approach on ligament function. Materials and Methods. Eight paired cadaveric hip joints were skeletonized but retained the hip capsule. Capsular ROM restraint during controlled internal rotation (IR) and external rotation (ER) was measured before and after HRA, DM-THA, and conventional THA, with a posterior (right hips) and anterior capsulotomy (left hips). Results. Hip resurfacing provided a near-native ROM with between 5° to 17° increase in IR/ER ROM compared with the native hip for the different positions tested, which was a 9% to 33% increase. DM-THA generated a 9° to 61° (18% to 121%) increase in ROM. Conventional THA generated a 52° to 100° (94% to 199%) increase in ROM. Thus, for conventional THA, the capsule function that exerts a limit on ROM is lost. It is restored to some extent by DM-THA, and almost fully restored by hip resurfacing. In positions of low flexion/extension, the posterior capsulotomy provided more normal function than the anterior, possibly because the capsule was shortened during posterior repair. However, in deep flexion positions, the anterior capsulotomy functioned better. Conclusion. Native head-size and capsular repair preserves capsular function after arthroplasty. The anterior and posterior approach differentially affect postoperative biomechanical function of the capsular ligaments. Cite this article: Bone Joint J 2019;101-B:426–434

Aims

Lateral femoral cutaneous nerve (LFCN) injury is a potential complication after the direct anterior approach for total hip arthroplasty (DAA-THA). The aim of this study was to determine how the location of the fasciotomy in DAA-THA affects LFCN injury.

Aims

Periprosthetic femoral fracture (PPF) is a major complication following total hip arthroplasty (THA). Uncemented femoral components are widely preferred in primary THA, but are associated with higher PPF risk than cemented components. Collared components have reduced PPF rates following uncemented primary THA compared to collarless components, while maintaining similar prosthetic designs. The purpose of this study was to analyze PPF rate between collarless and collared component designs in a consecutive cohort of posterior approach THAs performed by two high-volume surgeons.

Aims

The aim of this study was to investigate whether anterior pelvic plane-pelvic tilt (APP-PT) is associated with distinct hip pathomorphologies. We asked: is there a difference in APP-PT between young symptomatic patients being evaluated for joint preservation surgery and an asymptomatic control group? Does APP-PT vary among distinct acetabular and femoral pathomorphologies? And does APP-PT differ in symptomatic hips based on demographic factors?

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.

Injuries to the quadriceps muscle group are common in athletes performing high-speed running and kicking sports. The complex anatomy of the rectus femoris puts it at greatest risk of injury. There is variability in prognosis in the literature, with reinjury rates as high as 67% in the severe graded proximal tear. Studies have highlighted that athletes can reinjure after nonoperative management, and some benefit may be derived from surgical repair to restore function and return to sport (RTS). This injury is potentially career-threatening in the elite-level athlete, and we aim to highlight the key recent literature on interventions to restore strength and function to allow early RTS while reducing the risk of injury recurrence. This article reviews the optimal diagnostic strategies and classification of quadriceps injuries. We highlight the unique anatomy of each injury on MRI and the outcomes of both nonoperative and operative treatment, providing an evidence-based management framework for athletes.

Cite this article: Bone Joint J 2023;105-B(12):1244–1251.

Aims

In the UK, the agricultural, military, and construction sectors have stringent rules about the use of hearing protection due to the risk of noise-induced hearing loss. Orthopaedic staff may also be at risk due to the use of power tools. The UK Health and Safety Executive (HSE) have clear standards as to what are deemed acceptable occupational levels of noise on A-weighted and C-weighted scales. The aims of this review were to assess the current evidence on the testing of exposure to noise in orthopaedic operating theatres to see if it exceeds these regulations.

Aims

The surgical target for optimal implant positioning in robotic-assisted total knee arthroplasty remains the subject of ongoing discussion. One of the proposed targets is to recreate the knee’s functional behaviour as per its pre-diseased state. The aim of this study was to optimize implant positioning, starting from mechanical alignment (MA), toward restoring the pre-diseased status, including ligament strain and kinematic patterns, in a patient population.

Aims

Although CT is considered the benchmark to measure femoral version, 3D biplanar radiography (hipEOS) has recently emerged as a possible alternative with reduced exposure to ionizing radiation and shorter examination time. The aim of our study was to evaluate femoral stem version in postoperative total hip arthroplasty (THA) patients and compare the accuracy of hipEOS to CT. We hypothesize that there will be no significant difference in calculated femoral stem version measurements between the two imaging methods.

Aims. Recently, there has been considerable interest in quantifying the associations between bony abnormalities around and in the hip joint and osteoarthritis (OA). Our aim was to investigate the relationships between acetabular undercoverage, acetabular overcoverage, and femoroacetabular impingement (FAI) with OA of the hip, which currently remain controversial. . Materials and Methods. A total of 545 cadaveric skeletons (1090 hips) from the Hamann-Todd osteological collection were obtained. Femoral head volume (FHV), acetabular volume (AV), the FHV/AV ratio, acetabular version, alpha angle and anterior femoral neck offset (AFNO) were measured. A validated grading system was used to quantify OA of the hip as minimal, moderate, or severe. Multiple linear and multinomial logistic regression were used to determine the factors that correlated independently with the FHV, AV, and the FHV/AV ratio. . Results. Female cadavers had smaller FHVs (standardised beta -0.382, p < 0.001), and AVs (standardised beta -0.351, p < 0.001), compared with male patients, although the FHV/AV ratio was unchanged. Every 1° increase in alpha angle increased the probability of having moderate OA of the hip compared with minimal OA by 7.1%. Every 1 mm decrease in AFNO increased the probability of having severe or moderate OA of the hip, compared with minimal OA, by 11% and 9%, respectively. The relative risk ratios of having severe OA of the hip compared with minimal OA were 7.2 and 3.3 times greater for acetabular undercoverage and overcoverage, respectively, relative to normal acetabular cover. . Conclusion . Acetabular undercoverage and overcoverage were independent predictors of increased OA of the hip. The alpha angle and AFNO had modest effects, supporting the hypothesis that bony abnormalities both in acetabular dysplasia and FAI are associated with severe OA. Cite this article: Bone Joint J 2017;99-B:432–9

We hypothesised that the anterior and posterior walls of the body of the first sacral vertebra could be visualised with two different angles of inlet view, owing to the conical shape of the sacrum. Six dry male cadavers with complete pelvic rings and eight dry sacrums with K-wires were used to study the effect of canting (angling the C-arm) the fluoroscope towards the head in 5° increments from 10° to 55°. Fluoroscopic images were taken in each position. Anterior and posterior angles of inclination were measured between the upper sacrum and the vertical line on the lateral view. Three authors separately selected the clearest image for overlapping anterior cortices and the upper sacral canal in the cadaveric models. The dry bone and K-wire models were scored by the authors, being sure to check whether the K-wire was in or out. In the dry bone models the mean score of the relevant inlet position of the anterior or posterior inclination was 8.875 (standard deviation (. sd. ) 0.35), compared with the inlet position of the opposite inclination of –5.75 (. sd. 4.59). We found that two different inlet views should be used separately to evaluate the borders of the body of the sacrum using anterior and posterior inclination angles of the sacrum, during placement of iliosacral screws. Cite this article: Bone Joint J 2015;97-B:705–10

Aims

Reconstruction after osteoarticular resection of the proximal ulna for tumours is technically difficult and little has been written about the options that are available. We report a series of four patients who underwent radial neck to humeral trochlea transposition arthroplasty following proximal ulnar osteoarticular resection.

Injury to the triangular fibrocartilage complex (TFCC) may result in ulnar wrist pain with or without instability. One component of the TFCC, the radioulnar ligaments, serve as the primary soft-tissue stabilizer of the distal radioulnar joint (DRUJ). Tears or avulsions of its proximal, foveal attachment are thought to be associated with instability of the DRUJ, most noticed during loaded pronosupination. In the absence of detectable instability, injury of the foveal insertion of the radioulnar ligaments may be overlooked. While advanced imaging techniques such as MRI and radiocarpal arthroscopy are well-suited for diagnosing central and distal TFCC tears, partial and complete foveal tears without instability may be missed without a high degree of suspicion. While technically challenging, DRUJ arthroscopy provides the most accurate method of detecting foveal abnormalities. In this annotation the spectrum of foveal injuries is discussed and a modified classification scheme is proposed.

Cite this article: Bone Joint J 2023;105-B(1):5–10.

Total hip and knee arthroplasty (THA, TKA) are largely successful procedures; however, both have variable outcomes, resulting in some patients being dissatisfied with the outcome. Surgeons are turning to technologies such as robotic-assisted surgery in an attempt to improve outcomes. Robust studies are needed to find out if these innovations are really benefitting patients. The Robotic Arthroplasty Clinical and Cost Effectiveness Randomised Controlled Trials (RACER) trials are multicentre, patient-blinded randomized controlled trials. The patients have primary osteoarthritis of the hip or knee. The operation is Mako-assisted THA or TKA and the control groups have operations using conventional instruments. The primary clinical outcome is the Forgotten Joint Score at 12 months, and there is a built-in analysis of cost-effectiveness. Secondary outcomes include early pain, the alignment of the components, and medium- to long-term outcomes. This annotation outlines the need to assess these technologies and discusses the design and challenges when conducting such trials, including surgical workflows, isolating the effect of the operation, blinding, and assessing the learning curve. Finally, the future of robotic surgery is discussed, including the need to contemporaneously introduce and evaluate such technologies.

Cite this article: Bone Joint J 2024;106-B(2):114–120.