Aims. The aim of this study was to evaluate the clinical and radiological outcomes of locking plate fixation, with and without an associated fibular strut allograft, for the treatment of displaced proximal humeral fractures in elderly osteoporotic patients. Patients and Methods. We undertook a retrospective comparison of two methods of fixation, using a locking plate without an associated fibular strut allograft (LP group) and with a fibular allograft (FA group) for the treatment of these fractures. The outcome was assessed for 52 patients in the LP group and 45 in the FA group, with a mean age of 74.3 years (52 to 89), at a mean follow-up of 14.2 months (12 to 19). The clinical results were evaluated using a visual analogue scale (VAS) score for pain, the Constant score, the American Shoulder and Elbow Surgeons (ASES) score, and the range of movement. Radiological results were evaluated using the neck-shaft angle (NSA) and humeral head height (HHH). Results. The mean forward elevation in the LP and FA groups was 125.3° (. sd. 21.4) and 148.9° (. sd. 19.8), respectively (p = 0.042), while other clinical factors showed no statistically significant differences between the groups. The changes in NSA and HHH immediately after the operation and at final follow-up were significantly better in the FA group than in the LP group (p = 0.015 and p = 0.021, respectively). Conclusion. For comminuted proximal humeral fractures in osteoporotic patients, locking plate fixation with a fibular strut allograft shows satisfactory short-term results with respect to humeral head support and maintenance of reduction, and may reduce the incidence of complications associated with fixation using a locking plate alone. Cite this article: Bone Joint J 2019;101-B:260–265

Ten patients, who were unsuitable for limb lengthening over an intramedullary nail, underwent lengthening with a submuscular locking plate. Their mean age at operation was 18.5 years (11 to 40). After fixing a locking plate submuscularly on the proximal segment, an external fixator was applied to lengthen the bone after corticotomy. Lengthening was at 1 mm/day and on reaching the target length, three or four screws were placed in the plate in the distal segment and the external fixator was removed. All patients achieved the pre-operative target length at a mean of 4.0 cm (3.2 to 5.5). The mean duration of external fixation was 61.6 days (45 to 113) and the mean external fixation index was 15.1 days/cm (13.2 to 20.5), which was less than one-third of the mean healing index (48 days/cm (41.3 to 55). There were only minor complications. Lengthening with a submuscular locking plate can successfully permit early removal of the fixator with fewer complications and is a useful alternative in children or when nailing is difficult

Aims. To determine whether half-threaded screw holes in a new titanium locking plate design can substantially decrease the notch effects of the threads and increase the plate fatigue life. Methods. Three types (I to III) of titanium locking plates were fabricated to simulate plates used in the femur, tibia, and forearm. Two copies of each were fabricated using full- and half-threaded screw holes (called A and B, respectively). The mechanical strengths of the plates were evaluated according to the American Society for Testing and Materials (ASTM) F382-14, and the screw stability was assessed by measuring the screw removal torque and bending strength. Results. The B plates had fatigue lives 11- to 16-times higher than those of the A plates. Before cyclic loading, the screw removal torques were all higher than the insertion torques. However, after cyclic loading, the removal torques were similar to or slightly lower than the insertion torques (0% to 17.3%), although those of the B plates were higher than those of the A plates for all except the type III plates (101%, 109.8%, and 93.8% for types I, II, and III, respectively). The bending strengths of the screws were not significantly different between the A and B plates for any of the types. Conclusion. Removing half of the threads from the screw holes markedly increased the fatigue life of the locking plates while preserving the tightness of the screw heads and the bending strength of the locking screws. However, future work is necessary to determine the relationship between the notch sensitivity properties and titanium plate design. Cite this article: Bone Joint Res 2020;9(10):645–652

Objectives. Screw plugs have been reported to increase the fatigue strength of stainless steel locking plates. The objective of this study was to examine and compare this effect between stainless steel and titanium locking plates. Methods. Custom-designed locking plates with identical structures were fabricated from stainless steel and a titanium alloy. Three types of plates were compared: type I unplugged plates; type II plugged plates with a 4 Nm torque; and type III plugged plates with a 12 Nm torque. The stiffness, yield strength, and fatigue strength of the plates were investigated through a four-point bending test. Failure analyses were performed subsequently. Results. For stainless steel, type II and type III plates had significantly higher fatigue strength than type I plates. For titanium, there were no significant differences between the fatigue strengths of the three types of plates. Failure analyses showed local plastic deformations at the threads of screw plugs in type II and type III stainless steel plates but not in titanium plates. Conclusion. The screw plugs could increase the fatigue strength of stainless steel plates but not of titanium plates. Therefore, leaving screw holes open around fracture sites is recommended in titanium plates. Cite this article: L-W. Hung, C-K. Chao, J-R. Huang, J. Lin. Screw head plugs increase the fatigue strength of stainless steel, but not of titanium, locking plates. Bone Joint Res 2018;7:629–635. DOI: 10.1302/2046-3758.712.BJR-2018-0083.R1

Although gradual bone transport may permit the restoration of large-diameter bones, complications are common owing to the long duration of external fixation. In order to reduce such complications, a new technique of bone transport involving the use of an external fixator and a locking plate was devised for segmental tibial bone defects. A total of ten patients (nine men, one woman) with a mean age at operation of 40.4 years (16 to 64) underwent distraction osteogenesis with a locking plate to treat previously infected post-traumatic segmental tibial defects. The locking plate was fixed percutaneously to bridge proximal and distal segments, and was followed by external fixation. After docking, percutaneous screws were fixed at the transported segment through plate holes. At the same time, bone grafting was performed at the docking site with the external fixator removed. The mean defect size was 5.9 cm (3.8 to 9.3) and mean external fixation index was 13.4 days/cm (11.8 to 19.5). In all cases, primary union of the docking site and distraction callus was achieved, with an excellent bony result. There was no recurrence of deep infection or osteomyelitis, and with the exception of one patient with a pre-existing peroneal nerve injury, all achieved an excellent or good functional result. With short external fixation times and low complication rates, bone transport with a locking plate could be recommended for patients with segmental tibial defects. Cite this article: Bone Joint J 2013;95-B:1667–72

Aims. The aim of this study was to explore why some calcar screws are malpositioned when a proximal humeral fracture is treated by internal fixation with a locking plate, and to identify risk factors for this phenomenon. Some suggestions can be made of ways to avoid this error. Methods. We retrospectively identified all proximal humeral fractures treated in our institution between October 2016 and October 2018 using the hospital information system. The patients’ medical and radiological data were collected, and we divided potential risk factors into two groups: preoperative factors and intraoperative factors. Preoperative factors included age, sex, height, weight, body mass index, proximal humeral bone mineral density, type of fracture, the condition of the medial hinge, and medial metaphyseal head extension. Intraoperative factors included the grade of surgeon, neck-shaft angle after reduction, humeral head height, restoration of medial support, and quality of reduction. Adjusted binary logistic regression and multivariate logistic regression models were used to identify pre- and intraoperative risk factors. Area under the curve (AUC) analysis was used to evaluate the discriminative ability of the multivariable model. Results. Data from 203 patients (63 males and 140 females) with a mean age of 62 years (22 to 89) were analyzed. In 49 fractures, the calcar screw was considered to be malpositioned; in 154 it was in the optimal position. The rate of malpositioning was therefore 24% (49/203). No preoperative risk factor was found for malpositioning of the calcar screws. Only the neck-shaft angle was found to be related to the risk of screw malpositioning in a multivariate model (with an AUC of 0.72). For the fractures in which the neck-shaft angle was reduced to between 130° and 150°, 91% (133/46) of calcar screws were in the optimal position. Conclusion. The neck-shaft angle is the key factor for the appropriate positioning of calcar screws when treating a proximal humeral fracture with a locking plate. We recommend reducing the angle to between 130° and 150°. Cite this article: Bone Joint J 2020;102-B(12):1629–1635

Objectives. Secondary fracture healing is strongly influenced by the stiffness of the bone-fixator system. Biomechanical tests are extensively used to investigate stiffness and strength of fixation devices. The stiffness values reported in the literature for locked plating, however, vary by three orders of magnitude. The aim of this study was to examine the influence that the method of restraint and load application has on the stiffness produced, the strain distribution within the bone, and the stresses in the implant for locking plate constructs. Methods. Synthetic composite bones were used to evaluate experimentally the influence of four different methods of loading and restraining specimens, all used in recent previous studies. Two plate types and three screw arrangements were also evaluated for each loading scenario. Computational models were also developed and validated using the experimental tests. Results. The method of loading was found to affect the gap stiffness strongly (by up to six times) but also the magnitude of the plate stress and the location and magnitude of strains at the bone-screw interface. Conclusions. This study demonstrates that the method of loading is responsible for much of the difference in reported stiffness values in the literature. It also shows that previous contradictory findings, such as the influence of working length and very large differences in failure loads, can be readily explained by the choice of loading condition. Cite this article: A. MacLeod, A. H. R. W. Simpson, P. Pankaj. Experimental and numerical investigation into the influence of loading conditions in biomechanical testing of locking plate fracture fixation devices. Bone Joint Res 2018;7:111–120. DOI: 10.1302/2046-3758.71.BJR-2017-0074.R2

Aims. The aim of this study was to compare patient-reported outcome measures (PROMs) and the Single Assessment Numerical Evaluation (SANE) score in patients treated with a volar locking plate for a distal radial fracture. Methods. This study was a retrospective review of a prospective database of 155 patients who underwent internal fixation with a volar locking plate for a distal radial fracture between August 2014 and April 2017. Data which were collected included postoperative PROMs (Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH) and Patient-Rated Wrist Evaluation (PRWE)), and SANE scores at one month (n = 153), two months (n = 155), three months (n = 144), six months (n = 128), and one year (n = 73) after operation. Patients with incomplete data were excluded from this study. Correlation and agreement between PROMs and SANE scores were evaluated. Subgroup analyses were carried out to identify correlations according to variables such as age, the length of follow-up, and subcategories of the PRWE score. Results. The Pearson correlation coefficient (r) between PROMs and SANE scores was -0.76 (p < 0.001) for DASH and -0.72 (p < 0.001) for PRWE, respectively. Limits of agreement between PROMs and ‘100-SANE’ scores were met for at least 93% of the data points. In subgroup analysis, there were significant negative correlations between PROMs and SANE scores for all age groups and for follow-up of more than six months. The correlation coefficient between PRWE subcategories and SANE score was -0.67 (p < 0.001) for PRWE pain score and -0.69 (p < 0.001) for PRWE function score, respectively. Conclusion. We found a significant correlation between postoperative SANE and PROMs in patients treated with a volar locking plate for a distal radial fracture. The SANE score is thus a reliable indicator of outcome for patients who undergo surgical treatment for a radial fracture. Cite this article: Bone Joint J 2020;102-B(6):744–748

Aim. The aim of this study was to compare the cost-effectiveness of intramedullary nail fixation and ‘locking’ plate fixation in the treatment of extra-articular fractures of the distal tibia. Patients and Methods. An economic evaluation was conducted from the perspective of the United Kingdom National Health Service (NHS) and personal social services (PSS), based on evidence from the Fixation of Distal Tibia Fractures (UK FixDT) multicentre parallel trial. Data from 321 patients were available for analysis. Costs were collected prospectively over the 12-month follow-up period using trial case report forms and participant-completed questionnaires. Cost-effectiveness was reported in terms of incremental cost per quality adjusted life year (QALY) gained, and net monetary benefit. Sensitivity analyses were conducted to test the robustness of cost-effectiveness estimates. Results. Mean NHS and PSS costs were significantly lower for patients treated with an intramedullary nail than for those treated with a locking plate (-£970, 95% confidence interval (CI) -1685 to -256; p = 0.05). There was a small increase in QALYs gained in the nail fixation group (0.01, 95% CI -0.03 to 0.06; p = 0.52). The probability of cost-effectiveness for nail fixation exceeded 90% at cost-effectiveness thresholds as low as £15 000 per additional QALY. The cost-effectiveness results remained robust to several sensitivity analyses. Conclusion. This trial-based economic evaluation suggests that nail fixation is a cost-effective alternative to locking plate fixation. Cite this article: Bone Joint J 2018;100-B:624–33

Malunion is the most common complication of the distal radius with many modalities of treatment available for such a problem. The use of bone grafting after an osteotomy is still recommended by most authors. We hypothesised that bone grafting is not required; fixing the corrected construct with a volar locked plate helps maintain the alignment, while metaphyseal defect fills by itself. Prospectively, we performed the procedure on 30 malunited dorsally-angulated radii using fixed angle volar locked plates without bone grafting. At the final follow-up, 22 wrists were available. Radiological evidence of union, correction of the deformity, clinical and functional improvement was achieved in all cases. Without the use of bone grafting, corrective open wedge osteotomy fixed by a volar locked plate provides a high rate of union and satisfactory functional outcomes

We evaluated the biomechanical properties of two different methods of fixation for unstable fractures of the proximal humerus. Biomechanical testing of the two groups, locking plate alone (LP), and locking plate with a fibular strut graft (LPSG), was performed using seven pairs of human cadaveric humeri. Cyclical loads between 10 N and 80 N at 5 Hz were applied for 1 000 000 cycles. Immediately after cycling, an increasing axial load was applied at a rate of displacement of 5 mm/min. The displacement of the construct, maximum failure load, stiffness and mode of failure were compared. The displacement was significantly less in the LPSG group than in the LP group (p = 0.031). All maximum failure loads and measures of stiffness in the LPSG group were significantly higher than those in the LP group (p = 0.024 and p = 0.035, respectively). In the LP group, varus collapse and plate bending were seen. In the LPSG group, the humeral head cut out and the fibular strut grafts fractured. No broken plates or screws were seen in either group. We conclude that strut graft augmentation significantly increases both the maximum failure load and the initial stiffness of this construct compared with a locking plate alone

Penetration of the dorsal screw when treating distal radius fractures with volar locking plates is an avoidable complication that causes lesions of the extensor tendon in between 2% and 6% of patients. We examined axial fluoroscopic views of the distal end of the radius to observe small amounts of dorsal screw penetration, and determined the ideal angle of inclination of the x-ray beam to the forearm when making this radiological view. Six volar locking plates were inserted at the wrists of cadavers. The actual screw length was measured under direct vision through a dorsal approach to the distal radius. Axial radiographs were performed for different angles of inclination of the forearm at the elbow. Comparing axial radiological measurements and real screw length, a statistically significant correlation could be demonstrated at an angle of inclination between 5° and 20°. The ideal angle of inclination required to minimise the risk of implanting over-long screws in a dorsal horizon radiological view is 15°. Cite this article: Bone Joint J 2013;95-B:1101–5

There is no consensus on the benefit of arthroscopically assisted reduction of the articular surface combined with fixation using a volar locking plate for the treatment of intra-articular distal radial fractures. In this study we compared the functional and radiographic outcomes of fluoroscopically and arthroscopically guided reduction of these fractures. Between February 2009 and May 2013, 74 patients with unilateral unstable intra-articular distal radial fractures were randomised equally into the two groups for treatment. The mean age of these 74 patients was 64 years (24 to 92). We compared functional outcomes including active range of movement of the wrist, grip strength and Disabilities of the Arm, Shoulder, and Hand scores at six and 48 weeks; and radiographic outcomes that included gap, step, radial inclination, volar angulation and ulnar variance. . There were no significant differences between the techniques with regard to functional outcomes or radiographic parameters. The mean gap and step in the fluoroscopic and arthroscopic groups were comparable at 0.9 mm (standard deviation. (sd). 0.7) and 0.7 mm (. sd. 0.7) and 0.6 mm (. sd. 0.6) and 0.4 mm (. sd. 0.5), respectively; p = 0.18 and p = 0.35). . Arthroscopic reduction conferred no advantage over conventional fluoroscopic guidance in achieving anatomical reduction of intra-articular distal radial fractures when using a volar locking plate. Cite this article: Bone Joint J 2015; 97-B:957–62

We treated 47 patients with a mean age of 57 years (22 to 88) who had a proximal humeral fracture in which there was a severe varus deformity, using a standard operative protocol of anatomical reduction, fixation with a locking plate and supplementation by structural allografts in unstable fractures. The functional and radiological outcomes were reviewed. At two years after operation the median Constant score was 86 points and the median Disabilities of the Arm, Shoulder and Hand score 17 points. Seven of the patients underwent further surgery, two for failure of fixation, three for dysfunction of the rotator cuff, and two for shoulder stiffness. The two cases of failure of fixation were attributable to violation of the operative protocol. In the 46 patients who retained their humeral head, all the fractures healed within the first year, with no sign of collapse or narrowing of the joint space. Longer follow-up will be required to confirm whether these initially satisfactory results are maintained

We investigated the static and cyclical strength of parallel and angulated locking plate screws using rigid polyurethane foam (0.32 g/cm. 3. ) and bovine cancellous bone blocks. Custom-made stainless steel plates with two conically threaded screw holes with different angulations (parallel, 10° and 20° divergent) and 5 mm self-tapping locking screws underwent pull-out and cyclical pull and bending tests. The bovine cancellous blocks were only subjected to static pull-out testing. We also performed finite element analysis for the static pull-out test of the parallel and 20° configurations. In both the foam model and the bovine cancellous bone we found the significantly highest pull-out force for the parallel constructs. In the finite element analysis there was a 47% more damage in the 20° divergent constructs than in the parallel configuration. Under cyclical loading, the mean number of cycles to failure was significantly higher for the parallel group, followed by the 10° and 20° divergent configurations. In our laboratory setting we clearly showed the biomechanical disadvantage of a diverging locking screw angle under static and cyclical loading

The purpose of this study was to evaluate the risk of late displacement after the treatment of distal radial fractures with a locking volar plate, and to investigate the clinical and radiological factors that might correlate with re-displacement. From March 2007 to October 2009, 120 of an original cohort of 132 female patients with unstable fractures of the distal radius were treated with a volar locking plate, and were studied over a follow-up period of six months. In the immediate post-operative and final follow-up radiographs, late displacement was evaluated as judged by ulnar variance, radial inclination, and dorsal angulation. We also analysed the correlation of a variety of clinical and radiological factors with re-displacement. Ulnar variance was significantly overcorrected (p < 0.001) while radial inclination and dorsal angulation were undercorrected when compared statistically (p <  0.001) with the unaffected side in the immediate post-operative stage. During follow-up, radial shortening and dorsal angulation progressed statistically, but none had a value beyond the acceptable range. Bone mineral density measured at the proximal femur and the position of the screws in the subchondral region, correlated with slight progressive radial shortening, which was not clinically relevant. Volar locking plating of distal radial fractures is a reliable form of treatment without substantial late displacement. Cite this article: Bone Joint J 2013;95-B:396–400

Bone loss secondary to primary or metastatic lesions of the proximal humerus remains a challenging surgical problem. Options include preservation of the joint with stabilisation using internal fixation or resection of the tumour with prosthetic replacement. Resection of the proximal humerus often includes the greater tuberosity and adjacent diaphysis, which may result in poor function secondary to loss of the rotator cuff and/or deltoid function. Preservation of the joint with internal fixation may reduce the time in hospital and peri-operative morbidity compared with joint replacement, and result in a better functional outcome. We included 32 patients with pathological fractures of the proximal humerus in this study. Functional and radiological assessments were performed. At a mean follow-up of 17.6 months (8 to 61) there was no radiological evidence of failure of fixation. The mean revised musculoskeletal Tumour Society functional score was 94.6% (86% to 99%). There was recurrent tumour requiring further surgery in four patients (12.5%). Of the 22 patients who were employed prior to presentation all returned to work without restrictions. The use of a locking plate combined with augmentation with cement extends the indications for salvage of the proximal humerus with good function in patients with pathological and impending pathological fractures

Aims. The aims of this study were to establish whether composite fixation (rail-plate) decreases fixator time and related problems in the management of patients with infected nonunion of tibia with a segmental defect, without compromising the anatomical and functional outcomes achieved using the classical Ilizarov technique. We also wished to study the acceptability of this technique using patient-based objective criteria. Patients and Methods. Between January 2012 and January 2015, 14 consecutive patients were treated for an infected nonunion of the tibia with a gap and were included in the study. During stage one, a radical debridement of bone and soft tissue was undertaken with the introduction of an antibiotic-loaded cement spacer. At the second stage, the tibia was stabilized using a long lateral locked plate and a six-pin monorail fixator on its anteromedial surface. A corticotomy was performed at the appropriate level. During the third stage, i.e. at the end of the distraction phase, the transported fragment was aligned and fixed to the plate with two to four screws. An iliac crest autograft was added to the docking site and the fixator was removed. Functional outcome was assessed using the Association for the Study and Application of Methods of Ilizarov (ASAMI) criteria. Patient-reported outcomes were assessed using the Musculoskeletal Tumor Society (MSTS) score. Results. The mean age of patients was 38.1 years (. sd. 12.7). There were 13 men and one woman. The mean size of the defect was 6.4 cm (. sd. 1.3). the mean follow-up was 33.2 months (24 to 50). The mean external fixator index was 21.2 days/cm (. sd. 1.5). The complication rate was 0.5 (7/14) per patient. According to the classification of Paley, there were five problems and two obstacles but no true complications. The ASAMI bone score was excellent in all patients. The functional ASAMI scores were excellent in eight and good in six patients. The mean MSTS composite score was 83.9% (. sd. 7.1), with an MSTS emotional acceptance score of 4.9 (. sd. 0.5; maximum possible 5). Conclusion. Composite fixation (rail-plate) decreases fixator time and the associated complications, in the treatment of patients of infected nonunion tibia with a segmental defect. It also provides good anatomical and functional results with high emotional acceptance. Cite this article: Bone Joint J 2018;100-B:1094–9

We performed a retrospective study to determine the effect of osteoporosis on the functional outcome of osteoporotic distal radial fractures treated with a volar locking plate. Between 2009 and 2012 a total of 90 postmenopausal women with an unstable fracture of the distal radius treated with a volar locking plate were studied. Changes in the radiological parameters of 51 patients with osteoporosis (group 1, mean age 66.9, mean T-score –3.16 (. sd.  0.56)) were not significantly different from those in 39 patients without osteoporosis (group 2, mean age 61.1, mean T-score –1.72 (. sd. 0.57)). The mean Disabilities of the Arm, Shoulder and Hand (DASH) score at final follow-up was 11.5 (. sd. 12.2) in group 1 and 10.5 (. sd.  13.25) in group 2. The mean modified Mayo wrist score at final follow-up was 79.0 (. sd.  14.04) in group 1 and 82.6 (. sd. 13.1) in group 2. However, this difference was not statistically significant (p = 0.35 for DASH score, p = 0.2 for modified Mayo wrist score). Univariable and multivariable logistic regression analysis showed that only the step-off of the radiocarpal joint was related to both a poor DASH and modified Mayo wrist score. Pearson’s correlation coefficient showed a weak negative relationship only between the T-score and the change in volar tilt (intraclass coefficient –0.26, p = 0.02). We found that osteoporosis does not have a negative effect on the functional outcome and additional analysis did not show a correlation between T-score and outcome. Cite this article: Bone Joint J 2015;97-B:229–34

Filling the empty holes in peri-articular locking plates may improve the fatigue strength of the fixation. The purpose of this in vitro study was to investigate the effect of plugging the unused holes on the fatigue life of peri-articular distal femoral plates used to fix a comminuted supracondylar fracture model. A locking/compression plate was applied to 33 synthetic femurs and then a 6 cm metaphyseal defect was created (AO Type 33-A3). The specimens were then divided into three groups: unplugged, plugged with locking screw only and fully plugged holes. They were then tested using a stepwise or run-out fatigue protocol, each applying cyclic physiological multiaxial loads. All specimens in the stepwise group failed at the 770 N load level. The mean number of cycles to failure for the stepwise specimen was 25 500 cycles (. sd. 1500), 28 800 cycles (. sd.  6300), and 26 400 cycles (. sd. 2300) cycles for the unplugged, screw only and fully plugged configurations, respectively (p = 0.16). The mean number of cycles to failure for the run-out specimens was 42 800 cycles (. sd. 10 700), 36 000 cycles (. sd. 7200), and 36 600 cycles (. sd.  10 000) for the unplugged, screw only and fully plugged configurations, respectively (p = 0.50). There were also no differences in axial or torsional stiffness between the constructs. The failures were through the screw holes at the level of comminution. In conclusion, filling the empty combination locking/compression holes in peri-articular distal femur locking plates at the level of supracondylar comminution does not increase the fatigue life of the fixation in a comminuted supracondylar femoral fracture model (AO 33-A3) with a 6 cm gap