Aims. Posterior column plating through the single anterior approach reduces the morbidity in acetabular fractures that require stabilization of both the columns. The aim of this study is to assess the effectiveness of posterior column plating through the anterior intrapelvic approach (AIP) in the management of acetabular fractures. Methods. We retrospectively reviewed the data from R G Kar Medical College, Kolkata, India, from June 2018 to April 2023. Overall, there were 34 acetabulum fractures involving both columns managed by medial buttress plating of posterior column. The posterior column of the acetabular fracture was fixed through the AIP approach with buttress plate on medial surface of posterior column. Mean follow-up was 25 months (13 to 58). Accuracy of reduction and effectiveness of this technique were measured by assessing the Merle d’Aubigné score and Matta’s radiological grading at one year and at latest follow-up. Results. Immediate postoperative radiological Matta’s reduction accuracy showed anatomical reduction (0 to 1 mm) in 23 cases (67.6%), satisfactory (2 to 3 mm) in nine (26.4%), and unsatisfactory (> 3 mm) in two (6%). Merle d’Aubigné score at the end of one year was calculated to be excellent in 18 cases (52.9%), good in 11 (32.3%), fair in three (8.8%), and poor in two (5.9%). Matta’s radiological grading at the end of one year was calculated to be excellent in 16 cases (47%), good in nine (26.4%), six in fair (17.6%), and three in poor (8.8%). Merle d’Aubigné score at latest follow-up deteriorated by one point in some cases, but the grading remained the same; Matta’s radiological grading at latest follow-up also remained unchanged. Conclusion. Stabilization of posterior column through AIP by medial surface plate along the sciatic notch gives good stability to posterior column, and at the same time can avoid morbidity of the additional lateral window. Cite this article: Bone Jt Open 2024;5(2):147–153

Aims. The primary aim of this study was to address the hypothesis that fracture morphology might be more important than posterior malleolar fragment size in rotational type posterior malleolar ankle fractures (PMAFs). The secondary aim was to identify clinically important predictors of outcome for each respective PMAF-type, to challenge the current dogma that surgical decision-making should be based on fragment size. Methods. This observational prospective cohort study included 70 patients with operatively treated rotational type PMAFs, respectively: 23 Haraguchi Type I (large posterolateral-oblique), 22 Type II (two-part posterolateral and posteromedial), and 25 (avulsion-) Type III. There was no standardized protocol on how to address the PMAFs and CT-imaging was used to classify fracture morphology and quality of postoperative syndesmotic reduction. Quantitative 3D-CT (Q3DCT) was used to assess the quality of fracture reduction, respectively: the proportion of articular involvement; residual intra-articular: gap, step-off, and 3D-displacement; and residual gap and step-off at the fibular notch. These predictors were correlated with the Foot and Ankle Outcome Score (FAOS) at two-years follow-up. Results. Bivariate analyses revealed that fracture morphology (p = 0.039) as well as fragment size (p = 0.007) were significantly associated with the FAOS. However, in multivariate analyses, fracture morphology (p = 0.001) (but not fragment size (p = 0.432)) and the residual intra-articular gap(s) (p = 0.009) were significantly associated. Haraguchi Type-II PMAFs had poorer FAOS scores compared with Types I and III. Multivariate analyses identified the following independent predictors: step-off in Type I; none of the Q3DCT-measurements in Type II, and quality of syndesmotic reduction in small-avulsion Type III PMAFs. Conclusion. PMAFs are three separate entities based on fracture morphology, with different predictors of outcome for each PMAF type. The current debate on whether or not to fix PMAFs needs to be refined to determine which morphological subtype benefits from fixation. In PMAFs, fracture morphology should guide treatment instead of fragment size. Cite this article: Bone Joint J 2020;102-B(9):1229–1241

The purpose of this study was to describe the radiological characteristics of a previously unreported finding: posterior iliac offset at the sacroiliac joint and to assess its association with pelvic instability as measured by initial displacement and early implant loosening or failure. Radiographs from 42 consecutive patients with a mean age of 42 years (18 to 77; 38 men, four women) and mean follow-up of 38 months (3 to 96) with Anteroposterior Compression II injuries, were retrospectively reviewed. Standardised measurements were recorded for the extent of any diastasis of the pubic symphysis, widening of the sacroiliac joint, static vertical ramus offset and a novel measurement (posterior offset of the ilium at the sacroiliac joint identified on axial CT scan). Pelvic fractures with posterior iliac offset exhibited greater levels of initial displacement of the anterior pelvis (anterior sacroiliac widening, pubic symphysis diastasis and static vertical ramus offset, p < 0.001,0.034 and 0.028, respectively). Pelvic fractures with posterior ilium offset also demonstrated higher rates of implant loosening regardless of fixation method (p = 0.05). Posterior offset of the ilium was found to be a reliable and reproducible measurement with substantial inter-observer agreement (kappa = 0.70). Posterior offset of the ilium on axial CT scan is associated with greater levels of initial pelvic displacement and early implant loosening. Cite this article: Bone Joint J 2014;96-B:1535–9

Aims. The aim of this study was to investigate the effect of a posterior malleolar fragment (PMF), with < 25% ankle joint surface, on pressure distribution and joint-stability. There is still little scientific evidence available to advise on the size of PMF, which is essential to provide treatment. To date, studies show inconsistent results and recommendations for surgical treatment date from 1940. Materials and Methods. A total of 12 cadaveric ankles were assigned to two study groups. A trimalleolar fracture was created, followed by open reduction and internal fixation. PMF was fixed in Group I, but not in Group II. Intra-articular pressure was measured and cyclic loading was performed. Results. Contact area decreased following each fracture, while anatomical fixation restored it nearly to its intact level. Contact pressure decreased significantly with fixation of the PMF. In plantarflexion, the centre of force shifted significantly posteriorly in Group II and anteriorly in Group I. Load to failure testing showed no difference between the groups. Conclusion. Surgical reduction of a small PMF with less than 25% ankle joint surface improves pressure distribution but does not affect ankle joint stability. Cite this article: Bone Joint J 2018;100-B:95–100

We retrospectively analysed the clinical results of 30 patients with injuries of the sternoclavicular joint at a minimum of 12 months’ follow-up. A closed reduction was attempted in 14 cases. It was successful in only five of ten dislocations, and failed in all four epiphyseal disruptions. A total of 25 patients underwent surgical reduction, in 18 cases in conjunction with a stabilisation procedure.

At a mean follow-up of 60 months, four patients were lost to follow-up. The functional results in the remainder were satisfactory, and 18 patients were able to resume their usual sports activity at the same level. There was no statistically significant difference between epiphyseal disruption and sternoclavicular dislocation (p > 0.05), but the functional scores (Simple Shoulder Test, Disability of Arm, Shoulder, Hand, and Constant scores) were better when an associated stabilisation procedure had been performed rather than reduction alone (p = 0.05, p = 0.04 and p = 0.07, respectively).

We recommend meticulous pre-operative clinical assessment with CT scans. In sternoclavicular dislocation managed within the first 48 hours and with no sign of mediastinal complication, a closed reduction can be attempted, although this was unsuccessful in half of our cases. A control CT scan is mandatory. In all other cases, and particularly if epiphyseal disruption is suspected, we recommend open reduction with a stabilisation procedure by costaclavicular cerclage or tenodesis. The use of a Kirschner wire should be avoided.

Traumatic hip dislocation is a rare injury in orthopaedic practice and typically occures in high energy trauma. The goal of this study was to analyze hip morphology in patients with low energy traumatic hip dislocations and to compare it with a control group. We performed a retrospective comparative study. The study group included 45 patients with 45 traumatic posterior hip dislocation. Inclusion criteria were traumatic hip dislocation with simple acetabular rim or Pipkin I or II fracture. Traumatic dislocations combined with other acetabular or femoral fractures were excluded. The control group consisted of 90 patients (180 hips) that underwent radiographic examination for urogenital indication and had no history of hip pain. Hip morphology was assessed on antero-posterior and axial views. The study group showed significantly increased incidence (p<0.001) of positive cross-over sign (82% vs. 27%) with a increased retroversion index (26 ± 17 [0–56] vs. 6 ± 12 [0–53]), positive ischial spine sign (70% vs. 34%), and positive posterior wall sign (79% vs. 21). Hips that underwent an low energy posterior traumatic hip dislocation show significanly more radiographic signs for acetabular retroversion compared to a control group. Therefore, acetabular retroversion seems to be a contributing factor for posterior traumatic hip dislocation

Introduction. Sacral fractures were previously treated with transiliac bars, sacroiliac screws or posterior plates. Sacroiliac screws are not as invasive, but the risk of intra-operative neurovascular damage must be considered. Posterior plate fixation is slightly invasive. In 2006, we conceived a new fixation method with spinal instrumentation system, and I will introduce it. Procedure. We make 5cm skin incisions just above each side of post. sup. spine of ilium and make a tunnel under the soft tissue. Then, we insert 4 screws to ilium, pass two rods through the tunnel and fix them. If needed we make reduction or compression. Finally, set the transvers connecting device on both sides. Material and Method. We indicate this method for type C1 and C2 sacral fracture on AO classification. We treated 17 cases, C1 for 6 and C2 for 11 cases. We evaluated clinically and radiologically. Result. Mean operating time was 105 minutes, and mean hemorrhage was 125ml. We had 2 miss-directional insertions of screws out of 68 screws. We had 3 cases that complained of irritation pain around screw heads. No surgical site infection and no soft tissue necrosis. On radiological evaluation, we had no cases of correction loss, nonunion or implant failure. Conclusion. The advantages of our method are (1)easy and safety procedure, (2) high compatibility, (3)soft tissue protection, (4)stiffness of fixation, and (5)intraoperative manipulation, such as reduction or compression

We have evaluated the functional, clinical and radiological outcome of patients with simple and complex acetabular fractures involving the posterior wall, and identified factors associated with an adverse outcome. We reviewed 128 patients treated operatively for a fracture involving the posterior wall of the acetabulum between 1982 and 1999. The Musculoskeletal Functional Assessment and Short-Form 36 scores, the presence of radiological arthritis and complications were assessed as a function of injury, treatment and clinical variables. The patients had profound functional deficits compared with the normal population. Anatomical reduction alone was not sufficient to restore function. The fracture pattern, marginal impaction and residual displacement of > 2 mm were associated with the development of arthritis, which related to poor function and the need for hip replacement. It may be appropriate to consider immediate total hip replacement for patients aged > 50 years with marginal impaction and comminution of the wall, since 7 of 13 (54%) of these required early hip replacement

The purpose of this study is to analyze what kind of pattern of change in each posterior femoral condyle allows for a greater degree of flexion after total knee arthroplasty (TKA). The flexion angle was assessed pre-operatively, and at 12 months after the surgery in 98 patients (106 knees) who underwent consecutive TKA. We used a quantitative 3 dimensional technique using computed tomography for the assessment of changes in both the medial and lateral femoral condylar offset. There were no significant correlation between changes of each posterior condylar offset and post flexion angle (medial condyle; R=−0.038, p=0.70, lateral condyle; R=−0.090, p=0.36). There were no significant differences between changing patterns and increase rate of flexion (p=0.443). Additionally there were no significant differences between changing patterns and increase of flexion angle (p=0.593). Changes of each posterior condylar offset were no correlation to knee flexion after TKA in the current design prosthesis

Sacroiliac screw fixation is the method of choice for the definitive treatment of unstable posterior pelvic ring injuries; however this technique is demanding and associated with a high risk of iatrogenic neurovascular damage. We therefore evaluated the outcome, complications, surgical and fluoroscopy time for unstable posterior pelvic ring injuries managed with a transiliac locked compression plate. 23 patients were managed with a transiliac locked compression plate for unstable posterior pelvic injuries at a Level I Trauma Center. 21 patients were available for follow up after an average of 30 months and outcome evaluation was performed with the Pelvic Outcome Score, which is composed of a clinical, radiological, and social integration part. The overall outcome for the pelvic outcome score was excellent in 47.6% (10 patients), good in 19% (4 patients), fair in 28.6% (6 patients) and poor in 4.8% (1 patient). 15 out of 21 patients (71.4%) returned to their normal life, 3 patients (14.3%) were limited at work, and 3 patients (14.3%) were not able to return to work due to their disabilities. The social status was unchanged to the preinjury status in 19 patients (90.5%). 13 patients (62%) stated no changes in spare time and sports activities; 4 patients (19%) had minor and another 4 patients (19%) had major restrictions. The average operation time was 101 min and intraoperative fluoroscopic time averaged 74.2 sec. No iatrogenic neurovascular injuries were observed. Posterior percutaneous plate osteosynthesis may be a good alternative to sacral screw fixation because it is quick, safe, and associated with a good functional outcome

The equinovarus hind foot deformity is one of the most common deformities in children with spastic paralysis and is usually secondary to cerebral palsy. Split posterior tibialis tendon transfer is performed to balance the flexible spastic varus foot and is preferable to posterior tibialis lengthening, as the muscle does not loose its power and therefore the possibility of a valgus or calcaneovalgus deformity is diminished. The cohort of the study consisted of 50 children with cerebral palsy who underwent split posterior tibial lengthening to manage spastic equinovarus hind foot deformity. Our inclusion criteria were: ambulatory patients with cerebral palsy, age less than 6 years at the time of the operation, varus deformity of the hind foot during gait, flexible varus hind foot deformity, and the follow-up at least 4 years. We retrospectively evaluated 33 ambulant patients with flexible spastic varus hind foot deformity. Twenty-eight patients presented unilateral and 5 bilateral involvement. The mean age at the time of the operation was 10,8 years (6–17) and the mean follow-up was 10 years (4–14). Eighteen feet presented also equinus hind foot deformity, requiring concomitant Achilles cord lengthening. Clinical evaluation was based on the inspection of the patients while standing and walking, the range of motion of the foot and ankle, callus formation and the foot appearance using the clinical criteria of Kling et al. Anteroposterior and lateral weight-bearing radiographs of the talo-first metatarsal angle were measured. The position of the hind foot was evaluated according to the criteria of Chang et al for the surgical outcome. 20 feet were graded excellent, 14 were graded good and 4 were graded poor. Feet with recurrent equinovarus deformity or overcorrection into valgus or calcaneovalgus deformity were considered as poor results. There were 23 feet presenting concomitant cavus foot component that underwent supplementary operations performed at the same time with the index operation. None of the feet presented mild or severe valgus postoperatively, while 4 feet presented severe varus deformity and underwent calcaneocuboid fusion sixteen and eighteen months after the index operation. On the anteroposterior and lateral weight-bearing radiographs the feet with severe varus had a negative talo-first metatarsal angle (mean −26,8 ± 18,4), those with mild varus had a mean of −14,5 ± 12,2. In feet with the hind foot in neutral position the mean value was 5.0 ± 7.4. The results of the feet in patients with hemiplegic pattern were better and significantly different than the diplegic and quadriplegic ones (p = 0.005). The results in our cases were in general satisfactory as 34 out of 38 feet were graded excellent and good. The feet with poor results presented a residual varus deformity due to intraoperative technical errors

Both posterior and anterior surgery have potential for complete scoliosis correction. Significant difference in judging the procedures still persists. Aim. To establish objective advantages and risks of the procedures, basing upon long term results. Method. From 1982–2007, 859 anterior(A) and 388 posterior(P) instrumentations were performed by the same surgeon. Single level thoracotomy used even in double curves. Spinal canal was never opened, rib heads left intact, ribs were fractured at the top of rib hump. Zielke rod was used for correction, and another rod added for aditional correction and stabilisation. Various posterior instrumentations were used. Results. CORRECTION (A)frontal 67-45-16(76%), sagital +6, (P)frontal 66-44-29(56%), sag+3; OP. TIME (A)140(50–300), (P)155(110–350); BLOOD REPL. (A)18%, (P)92%; HOSP STAY (A)10, (P)13; VC (A)-10%, (P)0%; SPORT ACT. (A)3mths, (P)12mths; MAJOR COMPLICATIONS: no deaths, (A)1 aorta rupture, 1 bronchus penetration, 0,7% haematothorax, 0,6% reinstrumentation, 0,7% infections demanding op, (P)2 paraplegia (0,5%), 3.9% infections, 4.9% reinstrumentation. Discussion. (A)required no neuromonitoring, no intensive care unit. Blood replacement was occasionally used only for double curves (11 segm), and in preop. anemia. Most of the complications were preventable. Hospitalisation was longer in (P) group due to wound problems. Pulmonary decrease was found only in curves greater than 100 °. Halo traction improved VC, but both instr. had no influence on further improv. In (A)VC recovered in 6 months. Conclusions. (A) can be performed in less radical and agressive way. Anterior release significantly mobilizes the spine and decreases necessary corrective forces. Infection was more frequent in (P) but consequences were more dramatic in (A). All major complications in (A) were preventable. There is temporary decrease in pulmonary function after (A). We could not find objectives for (A) to have more morbidity than (P). Due to superior results we still prefer (A) in surgery of AIS. Our indications for (P) is VC<40%, age, poor bone quality, surgery in upper thoracic spine

Introduction. Although various reports analyzed “en-bloc” excision of sacral tumors, there are still technical problems to improve protection of nerve roots, preserve surrounding structures and reduce intraoperative bleeding, maintaining the oncologic result. We present a new technique for sacral resection, with short term preliminary results, derived with modification from Osaka technique. Methods. Seven patients were resected for their sacrococcygeal chordoma with the followed described technique. Two patients had previous surgery elsewhere. The sacrum is exposed by a posterior midline incision and complete soft-tissue dissection. Lateral osteotomies were performed through the sacral foramina using a threadwire saw and Kerrison rongeurs, to avoid sacral roots damage. After proximal osteotomy, the sacrum is laterally elevated and mobilized to allow dissection of presacral structures. Mean surgical time was 5 hours (range: 3 to 8). Mean blood loss was 3640 ml. Results. Level of resection was S1 in 2 pts, S2 in 4 pts, S3 in 1. Margins were wide in 6 patients and marginal in one. At a mean follow-up of 2 years, six patients were disease-free, one had a local recurrence. No complications were showed. Conclusion. This technique allows wide margins with roots preservation and reduction of complications and operative time. Indications for posterior approach only can be extended to resection proximal to S3, when there is minimal pelvic invasion and none or partial involvement of sacroiliac joints. However, the long term benefits of this technique need to be evaluated

This study reports on the natural history of acetabular fracture dislocations. We retrospectively reviewed patients who sustained an acetabular fracture associated with a posterior hip dislocation from a prospective database. Patient characteristics, complications and the requirement for further surgery were recorded. Patient outcomes were measured using the Oxford Hip score and Short Form SF-12 health survey. A total of 99 patients were treated over a 24 year period. The mean age was 41 years. Open reduction and internal fixation was performed in the majority (n=87), 10 were managed conservatively following closed reduction and two underwent primary total hip replacement (THR). At a median follow up of 12.4 years (range 4–24 years) patient outcomes were available for 53 patients. 12 patients had died. 19 patients went onto have a THR as a secondary procedure, of which 11 had confirmed avascular necrosis. Median time to THR was 2 years (range 1–17 years). The mean Oxford hip score was 35 (range 2–48), SF-12 physical component score (PCS) was 40 and a third of the patients used a walking aid. In THR group the mean Oxford score was 32 (range 3–46), SF-12 PCS was 39 and almost all required a walking aid. This is the first study to present the long term outcomes following an acetabular fracture dislocation. Our study suggests there is considerable disability in this group of patients and the requirement for subsequent THR has inferior patient reported outcomes

We hypothesised that an independent Notch Trial is essential on the same lines as other Component Trials-Femoral, Tibial and Patellar - in posterior stabilised total knee arthroplasty. Therefore we evolved Notch Trial to visually ascertain the adequacy of intercondylar resection and eliminate the possibility of femoral intercondylar fractures. We undertook a retrospective study to evaluate Notch Trial by the frequency of the need to remove osteophytes or file uneven surfaces in intercondylar resection by using the detachable box part of the trial femoral component, assess occurrence of distal femoral intercondylar fractures and demonstrate Notch Trial in posterior stabilised total knee replacement. We studied 206 patients, 113 females and 93 males, who underwent consecutive primary posterior stabilised total knee replacements applying Notch Trial between 2000 and 2008 in a District General Hospital under our team. Outcome Measurements were 1) frequency of the need to remove osteophytes or file uneven surfaces in intercondylar resection and 2) occurrence of distal femoral intercondylar fractures intraoperatively or on postoperative radiographs. We had to remove the osteophytes and file the cut surfaces in 183 (88.88%) of patients after Notch Trial. We had no distal femoral intercondylar fractures intraoperatively or on postoperative radiographs. Notch Trial allows the surgeon to directly visualise and ascertain the adequacy and precise fit of femoral notch cut with cam part of femoral component to ensure a press fit femoral component in condylar posterior cruciate substituting total knee replacement. Notch Trial prior to Femoral Component Trial effectively pre-empts intraoperative distal femoral intercondylar fractures. We recommend that Notch Trial should become part of the protocol for cruciate substituting total knee replacement and implants of all companies should have the option of a detachable box component for Notch Trial

Purpose of the Study. At our Department, we prefer surgical treatment of all patients with Type II and III fractures of the dens, regardless of the age, with the exception of non-displaced fractures or perfectly reduced fractures in young patients. Material and Methods. We treated surgically 28 patients 65 years old and older with dens fractures. The group consisted of 13 men and 15 women with a mean age of 77.4 years (range, 65–90 years). According to the type of treatment, anterior srew fixation or posterior C1–C2 fixation, the whole cohort was divided into 2 groups that were subdivided into two age groups of patients 65–74 years old and 75 years old and older. The age group of patients 65–74 years old included 8 patients with a mean age of 68.5 years and the mean age of the age group of patients 75 and more years old was 81 years. The injury was caused in 22 cases by a fall, in 5 by a car accident. Only in 1 case the injury was caused differently. Neurological deficits were found in three patients, all of them Frankel D type. All patients with injury to the dens underwent radiograph examination in the lateral and transoral projections and CT scan including the sagittal and frontal reconstructions of the atlantoaxial complex and in most cases also MRI examination to eliminate injury to the transverse ligament of the atlas. Based on these examinations, the type of injury was determined and method of treatment indicated. Final retrospective evaluation of the patients was carried out at the interval of 12 to 78 months after the primary surgery (mean 31.3 months) taking into account aetiology of the injury, type of injury, neurological finding, method of treatment, union of the dens fracture line or, where appropriate, C1–C2 fusion, stability of the spine and the final outcome. Statistical analysis was based on X2-test. Results. Comparison of the two age groups showed a statistically significant difference in the mortality (p<0.05), with 0% in the younger group and 40% in the older group. In total, mortality within 6 weeks after the injury accounted for 28.6%. Comparison of surgical techniques revealed 21.4% mortality after anterior screw fixation of the dens and 35.7% mortality after posterior instrumented fusion. The difference was statistically insignificant (p>0.05). Of the 20 surviving patients, 11 were treated with anterior screw fixation and 9 with posterior instrumented fusion. In the two groups there was only one case of nonunion of the dens (9.1%) and one fibrous callus in the region of C1–C2 fusion and the fracture line in the dens (11.1%). The difference was again insignificant (p>0.05). Conclusions. Active surgical treatment conduces considerably to the improvement of the quality of life of elderly patients after dens fractures. Surgical technique should be tailored to the patient's general condition, and osteoporosis and degenerative changes of the spine in particular. Mortality is influenced by the patient's age rather than by the surgical technique used. Elderly patients with a neurological deficit mostly die of associated diseases regardless of the method of treatment

Various techniques have been used for the fixation of the posterior pelvis, each with disadvantages specific to the technique. In this study, a new protocol involving the placement of posterior pelvic screws in the CT suite is described and evaluated. A total of 66 patients with unstable pelvic ring injuries was stabilised under local anaesthesia with sedation. The mean length of time for the procedure was 26 minutes per screw. There were no technical difficulties or misplaced screws and no cases of infection or nonunion. All patients stated that they would choose to have the CT scan procedure again rather than a procedure requiring general anaesthesia. The charges for the procedure were approximately £1840 ($2800) per operation. CT-guided placement of iliosacral screws is a safe, feasible, and cost-effective alternative to radiologically-guided placement in the operating theatre in selected patients

We aimed to identify variables associated with clinical and radiological outcome following fractures of the acetabulum associated with posterior dislocation of the hip. Using a prospective database of 1076 such fractures, we identified 109 patients with this combined injury managed operatively within three weeks and followed up for two or more years. The patients had a mean age of 42 years (15 to 79), 78 (72%) were male, and 84 (77%) had been involved in motor vehicle accidents. Using multivariate analysis the quality of reduction of the fracture was identified as the only significant predictor of radiological grade, clinical function and the development of post-traumatic arthritis (p < 0.001). All patients lacking anatomical reduction developed arthritis whereas only 25.5% (24 patients) with an anatomical reduction did so (p = 0.05). The quality of the reduction of the fracture is the most important variable in forecasting the outcome for patients with this injury. The interval to reduction of the dislocation of the hip may be less important than previously described

INTRODUCTION. Surgical correction of spinal deformities in the growing child can be applied with or without fusion. Sublaminar wiring, first described by Luque, allows continuation of growth of the non-fused spine after correction of the deformity. Neurological complications and wire breakage are the main clinical problems during the introduction and removal of currently used sublaminar wires. In this pilot study a posterior hybrid construction with the use of a medical-grade UHMWPE (Dyneema Purity®) sublaminar wire was assessed in an ovine model. We hypothesized that such a hybrid construction can safely replace current titanium laminar wires, while providing sufficient stability of the non-fused spinal column with preservation of growth. MATERIALS AND METHODS. This study included 6 Tesselaar sheep, age 7±2months. Two pedicle screws (Legacy system, Medtronic) were placed at lumbar level. Four consecutive laminae were attached to two titanium bars (4.5 mm) using 3 mm diameter UHMWPE (Dyneema Purity®) on the left side and 5 mm diameter on the right side. The sublaminar wires were fixed with a double loop sliding knot and tightened with a tensioning device. As a control, in one animal titanium sublaminar wires (Atlas cable, Medtronic) were applied. After sacrifice the spine of the animals was harvested. Radiographs were taken and CT scans were performed. The vertebrae were dissected and placed in formaldehyde for macroscopic and histological evaluation. RESULTS. The animals were sacrificed after a (minimal) postoperative period of 15 weeks. One animal developed a wire fistula and one animal died the first postoperative day due to complications of the anesthesia. None of the 3 or 5 mm knots loosened and no neurological complications occurred. An average of 8.7 mm growth was seen over the segment operated on. Computed tomography confirmed the preserved stability. Even though no decortication was performed, variable bone bridges with fused levels were seen on CT. Macroscopic and histological analysis showed no inflammation at lamina and dura levels containing Dyneema Purity®, with the exception of the case with the fistula where it was observed locally. DISCUSSION. This pilot animal model study shows that the UHMWPE laminar wire made by Dyneema Purity® has good handling and tensioning properties and can provide sufficient stability in fusionless spinal instrumentation while allowing substantial growth. The examined model showed to be a feasible spinal study model, without occurrence of neurological problems. Reactive periostal bone formation with fusion levels led to some restrictions in this model. In the future it will be necessary to test the described construction in a large animal scoliosis model

Introduction. While clinically successful for decades, CR TKA is persistently compromised by inconsistent PCL function. Problems of mid-flexion instability, incomplete knee flexion, erratic kinematic behavior and posterior instability, not seen with PS devices, raise concerns about the consistency of the technique, and the devices used. Most TKA systems offer at least 2 different geometries of tibial inserts to address this clinical problem. We hypothesize these problems are a result of compromise of PCL anatomy. To avoid compromise to the PCL 3 steps are required: 1) The slope of tibial resection must be less than 5°; 2) the depth of tibial resection must be based off the insertion footprint of the PCL, not the deficiencies of the tibial articular surface; and 3) the tibial insert must be modified to allow intraoperative balancing of the PCL. Results. The CR Slope ™ implants and technique (Exactech) (“Posterior Cruciate Referencing Technique (PCRT)”) reflect this philosophy and have allowed consistent surgical intervention without PCL release and without multiple inserts. We present data identifying, the footprint, and the instrument and technique modifications that allow for predictable identification of the depth and angle of resection. At 2 years post implantation in the first 100 patients implanted, the study group has demonstrated similar operative time, LOS and Oxford knee scores (OKS), while ROM averaged 5° greater, and time to achieved flexion was decreased. Conclusion. The PCRT offers a new conceptual and clinical approach to predictable CR TKA