Aims

Historically, patients undergoing surgery for adolescent idiopathic scoliosis (AIS) have been nursed postoperatively in a critical care (CC) setting because of the challenges posed by prone positioning, extensive exposures, prolonged operating times, significant blood loss, major intraoperative fluid shifts, cardiopulmonary complications, and difficulty in postoperative pain management. The primary aim of this paper was to determine whether a scoring system, which uses Cobb angle, forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and number of levels to be fused, is a valid method of predicting the need for postoperative critical care in AIS patients who are to undergo scoliosis correction with posterior spinal fusion (PSF).

Introduction

The health sector contributes the equivalent of 4.4% of global net emissions to the climate carbon footprint. It has been suggested that between 20% and 70% of health care waste originates from a hospital's operating room, the second greatest component of this are the textiles used, and up to 90% of waste is sent for costly and unneeded hazardous waste processing.

Waste from common orthopaedic operations was quantified, the carbon footprint calculated, and cost of disposal assessed. A discussion of the circular economy of textiles, from the author of the textile guidance to the Green Surgery Report follows.

Abstract

Introduction

Perioperative antibiotic prophylaxis use in modern orthopaedic procedures is well established. Studies have shown significant reduction in risk of post-operative infections. However, as effectiveness of these antibiotics is dependent on achieving high serum and tissue concentrations that exceed the minimum inhibitory concentrations of infective organisms for operation duration, the timing of prophylaxis is crucial. Although, optimal timing for administering prophylaxis varies in the literature, 30 to 60 minutes prior to skin incision or inflation of tourniquet is considered best standards.

Most long-term follow-up studies report retrospective data, the quality of which remains limited due to their inherent biases. Prospective databases may overcome these limitations, however, feasibility and costs limit their application. To date there exists a paucity of evidence-based literature on which recommendations can be made for the ideal length of follow-up for spinal deformity research. Therefore, our aim was to evaluate the added value of follow-up of patients beyond 2 years following surgery for AIS.

A database registry evaluating surgical outcomes for all consecutive AIS patients with post-op data-points of 6 months, 1 year, 2 year, and 5 year was analysed. Surgeon-reported complications, SRS-22 scores, and radiographic data were evaluated. Complications requiring surgical or medical intervention were compared between patients in whom complications developed within 2 years to those in which newly developed complications occurred between >2–5 years.

536 patients were analysed. SRS-22 scores significantly improved at 2 years post-op with no change at 5-year follow-up. Overall complication rate was 33.2% with majority occurring within 2 years (24.8%). The rate of complications occurring >2–5 years requiring intervention was significantly lower than those requiring intervention within 2 years of surgery (4.7% vs 9.7%, p=0.000), however was not negligible. The most common newly observed complication beyond 2 years was pain (1.9%), followed by surgical site infection (SSI) (1.3%) and implant issues (0.56%). There were no significant differences in the rates of crankshaft (p=0.48), implant issues (p=0.56), pseudarthrosis (p=0.19), and SSI (p=0.13) between the 2 time points.

Although majority of complications following AIS surgery occurs within 2 years, a non-negligible rate of newly observed complications occur at >2–5 years post-op. Specifically crankshaft, pseudarthrosis, implant issues, and SSI have similar rates of occurrence at these 2 time points.

Natural history of AIS >30° in skeletally mature patients is poorly defined. Studies reporting rates and risk factors for progression are predominantly of large curves in immature patients. Our aim was to determine the rate of curve progression in AIS following skeletal maturity, any associated changes in SRS-22 scores, and identify any potential predictors of curve progression.

Patients enrolled in a prospective, longitudinal, multicentre non-surgical AIS database were evaluated. All patients had minimum 2 year follow-up, idiopathic scoliosis >30°, and were skeletally mature. SRS-22 functional outcome scores and radiographic data were compared at baseline and 2-year follow-up. Patients were divided into 3 groups based on curve size: A=30°-39°, B=40°-49°, C= >50°. Curve progression was defined as any change in curve magnitude.

There were 80 patients, majority females (93.8%) with a mean age of 16.5+/−0.16. Mean BMI was 21+/−0.31 with 15.1% overweight. Mean major cobb at baseline was 38.3°+/−0.88°. At 2 year follow-up 46.3% of curves had progressed an average 3.4°+/−0.38°. Of curves that progressed, patients in group A had the largest mean rate of progression followed by group B. SRS-22 scores on average declined significantly over 2 years in this cohort (4.23 to 4.08; p=0.002). Patients who progressed had on average a more significant decline in SRS outcome scores compared to those that did not (p=0.018, p=0.041 respectively), with the most significant change noted in the Self-Image domain (p=0.03). There was no significant difference in the change in SRS scores over 2 years based on curve size. Univariate analysis did not identify any factors predictive of curve progression in this cohort.

Skeletally mature patients with AIS >30°may continue to have a risk of progression at a mean rate of 1.7°/yr and significant decline in SRS-22 outcome scores, in particular Pain and Self-Image, over time.

Introduction

Dislocation is one of the leading causes of revision after primary total hip arthroplasty (THA). Polyethylene wear is one of the risk factors for late dislocations (>2 years). It can induce an inflammatory response resulting in distension and thinning of the pseudocapsule, predisposing the hip to dislocation. Alternatively, eccentric seating of the femoral head in a worn out socket may result in an asymmetric excursion arc predisposing the hip to impingement, levering out and dislocation. Highly cross linked polyethylene has a significantly lower wear rate as compared to conventional polyethylene. Incidence of late dislocations has been shown to be significantly greater with conventional polyethylene bearings as compared to ceramic bearings. However, there is no literature comparing the risk of dislocation between ceramic- on- ceramic (CoC) bearings with metal/ceramic- on- cross linked polyethylene (M/CoP) bearings and this was the aim our study

There is strong evidence to support the use of bisphosphonates in the prevention of osteoporotic fractures. There has, however, been growing concern that prolonged use of bisphosphonates can lead to the development of atypical femoral fractures and can protract healing time.

We conducted a retrospective study looking at all femoral fractures between 2011–2013. Of 109 patients, 12 were diagnosed with atypical femoral fractures. The mean age of presentation was 69 (52–92). Five patients held no history of falls and presented with hip pain. The remaining seven sustained minor falls. Seven patients were on bisphosphonates on presentation. Bisphosphonates were discontinued in five cases and continued in two. Bisphosphonates commenced in one patient who subsequently developed second fracture. All fractures were managed with intramedullary nailing. Healing time was prolonged in all cases (mean healing time 7.3 months). Three patients needed further surgeries to achieve union.

Overall, we observed that patients with prolonged bisphosphonate intake were more susceptible to atypical fractures with a delayed recovery time.

Increasing awareness amongst medical professionals may aid timely diagnoses and subsequent referrals to orthopaedics. Recognition of these fractures may also permit early discontinuation of bisphosphonates, which may prevent future fractures and reduced healing times.

Summary Statement

Computational models are the primary tools for efficient design-phase exploration of knee replacement concepts before in vitro testing. To improve design-phase efficiency, a subject-specific computational platform was developed that allows designers to assess devices in realistic conditions by directly integrating subject-specific experimental data in these models.

Background

Venous thromboembolism (VTE) is a common complication of pelvic and acetabular fracture fixation. There is, however, currently limited data to guide clinical decisions on thromboprophylaxis choice in these patients.

Introduction

Growing rods are used in the treatment of early-onset scoliosis. The aim of this technique is to achieve deformity correction while maintaining spinal growth. Gradual stiffening or spontaneous fusion of the spine can interfere with the ability to lengthen. Furthermore, diminished acquired length with serial distraction is common and needs to be evaluated and quantified. The purpose of this prospective study was to measure the forces and amount of distraction over time in patients with early-onset scoliosis treated with growing rods.

Background

Bone lesions in Ewing's sarcoma (ES/PNET) have been traditionally diagnosed with bone Scan. PET-scan is emerging as a promising investigative modality for detection of metastatic lesions. In this prospective study, we compare the utility of both to detect the metastatic sites.

Purpose: The wait for surgical treatment of scoliosis is long in some countries, especially in those with publicly funded health care systems. Long wait times may have serious consequences if the deformity increases during the wait period. This study was undertaken to determine the surgeon’s perspective of the type and magnitude of surgery required with specific emphasis on peri – and post-operative measures, for patients with scoliosis on prolonged waitlist times (> 6 months) for surgery.

Method: Radiographs from 11 patients who had a Cobb angle of at least 50 degrees and had waited 6 or more months for scoliosis surgery selected from the scoliosis database. All patients had antero-posterior (AP), AP bending, and lateral radiographs taken when the primary curve magnitude was 50 degrees and at the time of pre-operative planning. 22 radiographic sets and a questionnaire were sent to three different surgeons. The surgeons were blinded to the fact that these sets contained films of the same patients at two different time points. The questionnaire requested information with regard to the type of surgery and instrumentation they would use, other peri-operative measures, and time taken to return to normal activities.

Results: The mean curve progression in the 11 patients was 25 degrees over the time on the waitlist, from an average of 50 degrees to 75 degrees. The type of surgery the surgeon would likely perform changed from posterior instrumentation and fusion with a screw construct in all patients to anterior release and posterior instrumentation and fusion with a screw construct in 8 of the 11 patients, in at least one surgeon’s opinion. The mean estimated operative time increased by 2 hours. The mean estimated length of stay at the hospital increased by 1 day, and the estimated level of difficulty of surgery increased from 3/10 to 5/10.

Conclusion: From a surgeon’s perspective, waits of 6 months or more for scoliosis surgery are unacceptable as they lead to the need for a second anterior procedure that probably would have not been necessary had the operation occurred earlier. It also leads to increased operative time, blood loss, length of stay, and difficulty of surgery. This, in turn, increases unwarranted risks and costs.

Purpose: Optimal fixation for comminuted proximal humerus fractures is controversial. Complications using locked plates have been addressed by anatomic reduction or medial cortical support. The current study measured relative mechanical contributions of varus malalignment and medial cortical support.

Method: Forty synthetic humeri were divided into three groups, osteotomized, and fixed at 0, 10, and 20 degrees of varus malreduction with locked proximal humerus plates (AxSOS, Global model, Stryker, Mahwah, NJ, USA). This simulated mechanical medial support with the cortex intact. Axial, torsional, and shear stiffness were experimentally measured. Half of the specimens in each of the groups underwent a second osteotomy to create a segmental defect which simulated loss of medial support with the cortex removed. Axial, torsional, and shear stiffness experiments were repeated, followed by shear load to failure in 20 degrees of abduction.

Results: For isolated malreduction with the cortex intact, the repair construct at 0 degrees showed statistically equivalent or higher axial, torsional, and shear stiffness than other groups assessed. Subsequent removal of cortical support in half the specimens resulted in a drastic effect on axial, torsional, and shear stiffness at all varus angles. Repair constructs with the cortex intact at 0 and 10 degrees resulted in mean shear failure forces of 12965.4 N and 9341.1 N, respectively. These were statistically higher (p< 0.05) compared to most other groups tested. Specimens failed mainly by plate bending as the femoral head was pushed down medially and distally.

Conclusion: Anatomic reduction with the medial cortex intact was the stiffest construct after a simulated two-part fracture. This study also supports the practice of achieving medial cortical support by fixing proximal humeral fractures in varus if necessary. This may be preferable to fixing the fracture in anatomic alignment when there is a medial fracture gap.

Purpose: Minimizing tip-apex distance (TAD) has been shown to reduce clinical failure of extramedullary sliding hip screws used to fix peritrochanteric fractures. There is debate regarding the optimal position of the lag screw in the femoral head when a cephalomedullary nail is used to treat a peritrochanteric fracture. Some authors suggest the TAD should be minimized as with an extramedullary sliding hip screw, while others suggest the lag screw should be placed inferior within the femoral head. The primary goal of this study was to determine which of 5 possible lag screw positions in the femoral head provides greatest mechanical stiffness and/or load-to-failure for an unstable peritrochanteric fracture treated with a cepha-clomedullary nail. The secondary goal was to determine if there is a linear correlation between implant-femur mechanical stiffness and/or load to failure (dependent variables) with a series of five radiographic measurements (independent variables) of distance from the lag screw tip to the femoral head apex.

Method: Long Gamma 3 Nails (Stryker, Mahwah, NJ) were inserted into 30 left synthetic femurs (Pacific Research Laboratories, Vashon, WA). An unstable four-part fracture was created, anatomically reduced, and repaired using one of 5 lag screw placements in the femoral head:

superior (n=6),

All specimens were radiographed in the anterioposterior and lateral planes, and radiographic measurements including TAD and a calcar referenced tip-apex distance (CalTAD) were calculated. All specimens were tested for axial, lateral, and torsional stiffness, and then loaded-to-failure in the axial position using an Instron 8874 (Canton, MA). ANOVA was used to compare means of the five treatment groups. Linear regression analysis was used to compare stiffness and load-to-failure (dependant variables) with radiographic measurements (independent variables). A post hoc power analysis was performed.

Results: The inferior lag screw position had significantly greater mean axial stiffness than superior (p< 0.01), anterior (p=0.02) and posterior (p=0.04) positions. Analysis revealed significantly less mean torsional stiffness for the superior lag screw position compared to other lag screw positions (p< 0.01 all 4 pairings). No statistical differences were noted for lateral stiffness. Superior and central lag screw positions had significantly greater mean load-to-failure than anterior (p< 0.01 and p=0.02) and posterior (p< 0.01 and p=0.05) positions.

There were significant negative linear correlations between stiffness tests with CalTAD, and load-to-failure with TAD. Power was greater than 95% for axial stiffness, torsional stiffness and load-to-failure tests.

Conclusion: Position of the lag screw in the femoral head affects the biomechanical properties of the implant-femur construct. Central placement of the lag screw with minimization of TAD may provide the best combination of stiffness and load-to-failure.

Purpose: Cephalomedullary nails rely on a large lag screw that provides fixation into the femoral head. There is an option to statically lock the lag screw (static mode) or to allow the lag screw to move within the nail to compress the intertrochanteric fracture (dynamic mode). The purpose of this study was to compare the biomechanical stiffness of static and dynamic modes for a cephalomedullary nail used to fix an unstable peritrochanteric fracture.

Method: Thirty intact synthetic femur specimens (Model #3406, Pacific Research Laboratories, Vashon, WA) were potted into cement blocks distally for testing on an Instron 8874 (Instron, Canton, MA). A long cephalomedullary nail (Long Gamma 3 Nail, Stryker, Mahwah, NJ) was then inserted into each of the femurs. An unstable four-part fracture was created, anatomically reduced, and the cephallomedullary nail was reinserted. Mechanical tests were conducted for axial, lateral, and torsional stiffness with the lag screws in:

static and

A paired student’s t test was used to compare the 2 modes.

Results: The axial stiffness of the cephalomedullary nail was significantly greater (p< 0.01) in the static mode (484.3±80.2N/mm) than in the dynamic mode (424.1±78.0N/mm) (Fig.2A). Similarly, the lateral bending stiffness of the nail was significantly greater (p< 0.01) in the static mode (113.9±8.4N/mm) than in the dynamic mode (109.5±8.8N/mm). The torsional stiffness of the nail was significantly greater (p=0.02) in the dynamic mode (114.5±28.2N/mm) than in the static mode (111.7±27.0N/mm).

A post hoc power analysis with & #945;=0.05 and & #946;=0.20 revealed that the paired t test on 30 samples was sufficiently powered to determine a difference in mean axial stiffness of 33.0N/mm (6.8% of static stiffness), a difference in mean lateral bending stiffness of 3.6N/mm (3.2% of static stiffness) and a difference in mean torsional stiffness of 3.4N/mm (3.0% of static stiffness).

Conclusion: Our results show that there is a 60N/mm reduction in axial stiffness of the cephalomedullary nail when the lag screw is changed from static to dynamic mode. This represents a 12.4% reduction in axial stiffness with a change from axial to dynamic modes which may be clinically significant. The differences in lateral (4.4N/mm, 3.9%) and torsional (2.8N/mm, 2.4%) are small enough that they are likely not clinically significant. We felt that a difference of greater than 10% in axial stiffness and a difference of greater than 5% in lateral or torsional stiffness would be clinically significant. Our study was adequately powered to detect these differences. Given the significant reduction in axial stiffness with dynamization of the cephalomedullary nail construct, we recommend use of the static mode when treating unstable peritrochanteric fractures with a cephalomedullary nail.

Minimizing tip-apex distance has been shown to reduce clinical failure of sliding hip screws used to fix peritro-chanteric fractures. The purpose of this study was to determine if such a relationship exists for the position of the lag screw in the femoral head using a cephalomedullary device.

Methods: Thirty intact synthetic femur specimens (Model #3406, Pacific Research Laboratories, Vashon, WA) were potted into cement blocks distally for testing on an Instron 8874 (Instron, Canton, MA). A long cephalomedullary nail (Long Gamma 3 Nail, Stryker, Mahwah, NJ) was inserted into each of the femurs. An unstable four-part fracture was created, anatomically reduced, and repaired using one of 5 lag screw placements in the femoral head:

Superior (N=6),

Mechanical tests were repeated for axial, lateral and torsional stiffness. All specimens were radiographed in the anterioposterior and lateral planes and tip-apex (TAD) distance was calculated. A calcar referenced tip-apex distance (CalTAD) was also calculated.

ANOVA was used to compare means of the five treatment groups. Linear regression analysis was used to compare axial, lateral and torsional stiffness (dependant variables) to both TAD and CalTAD (independent variables).

Results: ANOVA testing proved that the mean axial (p< 0.01) and torsional stiffness (p< 0.01) between the 5 groups was significantly different, but lateral stiffness was not statistically different (p=0.494). Post hoc analysis showed that the inferior lag screw position provided significantly higher mean axial stiffness (568.14±66.9N/ mm) than superior (428.0±45.6N/mm; p< 0.01), anterior (443.2±45.4N/mm; p=0.02) and posterior (456.7±69.3N/ mm; p=0.04) lag screw positions. There was no significant difference in mean axial stiffness between inferior (568.14±66.9N/mm) and central (525.4±81.7N/mm) lag screw positions (p=0.77). Post hoc analysis revealed significantly less mean torsional stiffness for the superior lag screw position compared to other lag screw positions (p< 0.01 all 4 pairings). There were no significant correlations between TAD and axial (r=−0.33, p=0.08), lateral (r=−0.22, p=0.24) or torsional (r=0.08, p=0.69) stiffness. There were significant correlations between CalTAD and axial (r=−0.66, p< 0.01), lateral (r=−0.38, p=0.04) and torsional (r=−0.38, p=0.04) stiffness.

Discussion: Our results suggest that placement of the lag screw inferiorly in the femoral head when using a cephalomedullary nail to treat an unstable peritrochanteric fracture results in the stiffest construct in axial and torsional biomechanical testing. A simple radiographic measurement, CalTAD, provides an intraoperative method of determining optimal cephalomedullary nail lag screw position to achieve greatest construct stiffness.

Aim: To review our experience with hemi-epiphysiodesis using different methods for the correction of angular deformity about the knee.

Method: This was a retrospective review of 73 patients (101 knees) who underwent hemi-epiphysiodesis from 1999 to 2008. Assessment looked at the type and degree of deformity, implants used, average operating time and hospital stay, complications, degree of correction and the average time to correction.

Results: There were 50 boys and 23 girls with bilateral deformity in 28 cases. There were 88 valgus and 13 varus knees. Average follow-up was 17 months. Staples were used in 28 cases, “8” Plates in 24, Screws in 16 and Drilling in 5 cases. The distal femoral physis was involved in 46 knees, the proximal tibial physis in 21 and both physes in 34 knees (total 135 physes). Average operation time and hospital stay were similar for all methods. There were 6 minor and 3 major complications with staples with an average correction time of 14 months, 3 minor complications with an average correction time of 11 months with “8” plates, 3 minor and 1 major complication with an average correction time of 14 months with screws and 1 minor complication with drilling with an average correction time of 13 months. The outcome was considered as resolved in 47 and pending in 26 cases, with all showing progressive correction of deformity.

Conclusions: Hemi-epiphysiodesis by any method is an effective way to correct angular deformities about the knee in skeletally immature individuals within a reasonable time limit and with minimal morbidity when compared to a corrective osteotomy. Our experience suggests that “8” plates achieve faster correction with the least complications when compared to other methods. Valgus knee deformities corrected faster than varus ones.

The treatment algorithms for femoral neck fractures in elderly keep changing constantly and are still controversial because of increasing stress on improving the quality of life in elderly population and associated osteoporosis. Orthopedic surgeons have almost agreed to the advantages of arthroplasty over fixation in improving the outcome in elderly population, but differences still persist as to type of arthroplasty. Options include unipolar, bipolar or total hip arthroplasty. The objective of present study is to compare the outcome of bipolar and total hip arthroplasty in fracture neck femur in Indian elderly population.

A retrospective analysis was performed for comparing the quality of life index in 60 patients over the age of 55 years who underwent bipolar hemiarthroplasty (30 patients) or total hip arthroplasty (30 patients). The follow up period ranged from 3 months to 3 years. Patients were interviewed by an independent observer by questionnaires based on Harris Hip score and Hospital for special surgery score and were examined clinically. The results were analyzed using unpaired t-test.

Though the average period of stay for total hip arthroplasty group was significantly longer but it did not affect the quality of life after 3 months. Patients undergoing total hip replacement were found to be doing significantly better with regards to muscle power, range of motion and function as assessed by unpaired t-test (p < 0.05), but no statistical significant differences were found as far as pain and walking scores were concerned.

Total hip replacement provides a better quality of life to elderly patient with femoral neck fractures compared with bipolar hemiarthroplasty in Indian population.

The use of bisphosphonates in the treatment of avascular necrosis of the femoral head is an encouraging but relatively new option with most published data being derived from small trials with limited follow-up. We present a clinicoradiological analysis of 395 hips with avascular necrosis which were treated with oral alendronate for three years with a mean follow-up of four years (1 to 8).

Our results show an improvement in the clinical function, a reduction in the rate of collapse and a decrease in the requirement for total hip replacement, compared with the findings of other studies in which no treatment was given. This improvement is particularly marked if the treatment is begun in the pre-collapse stages of the disease. Even in Ficat stage-III hips some benefit was obtained from treatment with alendronate by at least a delay in the need for total hip replacement.